ABSTRACT. This paper proposed an analytical method for the calculation of electromagnetic toque in a Permanent Magnet-assisted Synchronous Reluctance Motor (PMASynRM) based on equivalent magnetic network model. The Fourier expression of the electromagnetic torque considering harmonic is theoretically analyzed and simulated. With the aim of reducing torque ripple, the effect of the flux barrier angle and PM thickness on the electromagnetic torque and torque ripple is theoretically studied and simulated in one pole asymmetry and one pole pairs asymmetry structure. Finally, the optimal flux barrier angle is given. There is a good consistence between theoretical and simulation result.

ABSTRACT. This digest provides a solution for design of permanent magnet (PM) assisted synchronous reluctance machine (PMa-SynRM). Differing to interior PM (IPM) machines, the PMa-SynRM is substantially a SynRM with a dominant reluctance torque rather than PM torque. Many studies regarding PMa-SynRM often embed magnets in a SynRM rotor and discussions are then made to compare performance improvement over the original SynRM. However, the effect of PM, such as position in the rotor, the number of layers embedded and the PM width have not been well discussed. This digest, with an attempt to enhance the performance of a PMa-SynRM, discusses upon the influence of several key factors concerning the insertion of PM. A suggest will be provided as a reference for design of the PMa-SynRM. Some theory is discussed and finite element analysis (FEA) is used to evaluate the performance. Finally, experimental studies are conducted to validate the simulations.

ABSTRACT. Hybrid permanent magnet (PM) variable flux memory (VFM) machines employ both the high coercive force PM, i.e. the constant PM (CPM), and the low coercive force PM, i.e. the variable PM (VPM), with which the PM magnetization state can be regulated to match various operation requirements. These two kinds of PMs can be connected with either parallel or series configuration so that different characteristics can be obtained. Based on two-dimensional (2-D) and three-dimensional (3-D) finite element (FE) analyses, the end effects of a pair of VFM machines with parallel and series connections respectively are investigated to highlight their different features.

ABSTRACT. In this paper rotor topologies of synchronous reluctance machines are compared with regard to electrical traction applications. Electrical machines for electric vehicles are usually operated in a wide speed range including flux weakening. In contrast to permanent magnet synchronous machines and induction machines synchronous reluctance machines have advantages of a very simple and cost effective rotor design, which makes this machine type very interesting for this application. For synchronous reluctance machines different rotor topologies as salient poles or flux barrier designs are known and both are investigated in this work regarding high speed operation in flux weakening range. Because of the mechanical strength limitation of flux barrier machines a salient pole machine is proposed, although design steps to accomplish the same machine harmonics characteristic of the salient pole type have to be implemented. Finally, both machines provide sufficient operation in the whole speed range. However, the machines show slightly different behavior and require different manufacturing technologies for the stator winding and the rotor.

ABSTRACT. Synchronous reluctance machine (SynRM) has attracted much attention thanks to the advantages such as low cost, rugged rotor structure and relatively high performance. Conventional drive for the SynRM is the same as that for permanent magnet synchronous machine (PMSM), i.e. the sine-wave drive. However, sine-wave drive needs complicated PWM strategy and high-cost rotor position sensor. In this paper, square-wave drive is proposed for the SynRM. The torque performances with square-wave drive are analyzed and feasible application is concluded. Besides, a-b-c phase inductance and d-q axis inductance models are established to demonstrate the torque component. Moreover, frozen permeability method is utilized to separate the current harmonic-caused torque ripple and inductance harmonic-caused torque ripple so as to illustrate the torque ripple resources.

ABSTRACT. We have proposed a claw pole type half-wave rectified variable field flux motor (CP-HVFM) with special self- excitation method. This paper reports the experimental results under the load condition and various speed command, and shows the fundamental output characteristics such as the voltage and the current, the efficiency. And we consider the influence of the variable field flux control on the fundamental characteristics.

ABSTRACT. In this paper, a novel single-phase hybrid switched reluctance motor (HSRM) is proposed for hammer breaker application. This motor has simple structure with non-uniform air-gap and produces low torque ripple. Permanent magnets (PM) are placed at parking positions for self-starting and to create positive cogging torque in the torque dead-zones. Compared with conventional single-phase switched reluctance motor, it has an increased torque density and relatively low torque ripple, along with a simpler structure. To verify effectiveness, finite element method (FEM) is employed to analyze the performance of the proposed structure. Comparison between the proposed motor and the existing motor drive system for hammer breaker application is demonstrated. Based on the analysis, a prototype motor is manufactured and tested. The experimental results are presented.

ABSTRACT. In this paper, a method of using the switched reluctance motor (SRM) to mimic an inductive rotor position sensor is presented. Based on the high frequency signal injection method, the unsaturated phase inductance of the sensor motor can be calculated indirectly for position estimation. The sensor motor has been tested for providing position signals for a coaxial motor drive. Experimental results verify the validity of the proposed method. This work shows that the new sensor possesses the robust structure and the basic electromagnetic characteristic of a SRM, which is able to be used in many harsh environmental application conditions.

ABSTRACT. This paper proposes a novel dynamic decoupling control algorithm for a single winding bearingless switched reluctance motor (BSRM), using extreme learning machine (ELM) identifier and inverse controller. Firstly, the working principle and mathematic model of BSRM are described and finite element method (FEM) is employed to get characteristic profiles. Then, the invisibility of mathematic model is analyzed and an ELM identifier is applied to identify the inverse model. To illustrate the superiority of ELM inverse model, comparisons are conducted with neural network (NN) and support vector machine (SVM). Finally, simulation results validate that the proposed algorithm can actualize dynamic decoupling control.

ABSTRACT. The paper presents combined clustering RBF neural network as a tool to develop the model of the SRM. Combined clustering algorithm is presented here to determine node number of hidden layer and center of RBF neural network self-adaptively. First, the subtractive clustering algorithm is used to find the initial clustering center. FCM(Fuzzy c-means) clustering algorithm is used for further adjustment and effectiveness evaluation. It can not only avoid falling into local optimal solution and improve the clustering speed, but also can automatically generate a good number of clusters according to the influence of each data point in each dimension of the cluster center. Then, data center and optimal network structure of radial basis function RBF neural network is achieved. The sampled data set is obtained from the experimental SRM by the finite elements method(FEM). The simulation results show that the model is reasonable and can reflect the electromagnetic characteristics of the motor. The established model is easy to extend, which provides the basis for the analysis and design of SRM control algorithm.

ABSTRACT. In order to reduce the torque ripple and improve the torque-speed characteristic of switched reluctance motor, a novel predictive current control method with torque sharing function (TSF) is proposed in this paper. Compared with conventional current hysteresis control, the current tracing ability is improved by using proposed method without increasing switch frequency or changing hysteresis band. Both of torque ripples and copper loss reduction of different TSFs are investigated in magnetic linear and saturation condition, respectively. Simulations and experiments with 5.5kw three-phase 12/8 SRM verify the effectiveness of the proposed control strategies all over speed range.

ABSTRACT. High speed brushless permanent-magnet generators (HSBPMGs) may be the most suitable choice for small solar co-generation systems due to a variety of merits. For instance, they offer substantial reduction in size, and thermally excellent high power density, which reduces the running costs with good performance and reliability. Moreover, high efficiencies i.e. over 90%, light-weight, low operating temperature, high insulation, no brushes/slip rings and almost negligible cogging torque make HSBPMGs ideal for co-generation systems. However, because of the very high rotor speed and high stator frequency, the design of HSBPMG is quite different from designing a conventional generator with low speed and low frequency. As the speed increases, the losses and temperature go up, and thus careful attention is needed while selecting the design parameters and material for the machine. This paper is aimed to use the basic design process for HSBPMGs running at 60,000rpm, with 6.6kW capacity keeping the losses minimum by using an appropriate material and cooling method. Finite element analysis of the machine is carried by using Motor-CAD simulation software, and modeling of a prototype machine is presented.

ABSTRACT. In this paper, a new modular linear Flux-switching permanent magnet machine is presented. The analysis of the proposed machine is carried out by the finite-element method. The optimization of this machine for ropeless elevator application is performed based on surrogate method. The characteristics of the new modular machine with different mover and stator pole pitch are compared.

ABSTRACT. This paper presents a biased flux hybrid-excited flux switching machine (BFHEFSM) to improve the flux-regulation capability of the machine. The proposed configuration uses E-core to enhance the permanent magnet (PM) material utilization ratio, which use half PMs of the conventional flux switching permanent magnet machine (FSPMM). The flux-regulation principle of the E-core BFHEFSM is discussed based on the biased field. However, due to the asymmetric saturation of the magnetic path, the back-EMF of the proposed E-core BFHEFSM occurs phase shift when the current of field winding changes, i.e., flux-regulating. A simple method, namely both the stator and rotor are segmented, is proposed to eliminate the phase shift. The results confirm the flux-regulation capability is favorable. It is demonstrated that the flux-regulation capability of the proposed machine is favorable.

ABSTRACT. In this paper, a new single-phase flux switching axial flux permanent magnet motor (FS AFPM) is presented. It has a double stator and single rotor (DSSR) disc-type structure. The rotor disc is a simple salient pole rotor, and it is sandwiched between the two stator discs. The permanent magnets (PMs) are embedded in the stator discs, which also contain the single-phase windings. To enhance the self-starting torque capability and unidirectional rotation, the rotor pole is chamfered. The characteristic analysis of the proposed DSSR type single-phase FS AFPM is carried out using the 3D finite element analysis (FEA).

ABSTRACT. A kind of arc-linear axial flux permanent-magnet synchronous machine (AL-AF-PMSM) used for scanning system is researched in this paper. Due to the characteristics of the three-dimensional (3-D) magnetic field, 3-D finite element method (FEM) is usually required to analyze the AF-PMSM. However, 3-D FEM is generally too time consuming. In order to avoid this problem, an approximate equivalent 2-D calculating model is proposed based on the idea of Complex Simpson integral formula. Then this method is validated by comparing with the 3-D FEM results. Finally, with the help of this new method, the AL-AF-PMSM is optimized to reduce the torque fluctuation and improve the smooth operating range.

ABSTRACT. In this paper, a modular multilevel converter (MMC) integrated ultracapacitors energy storage system (UCESS) are proposed for Power Router. Half bridges integrated with UC modules are utilized as the sub-module (SM) of the converter. Due to the integration of UCESS, the input power and output power can be decoupled, which means that the power relationship of the Power Router can be flexible. This paper analyzes the topology and mathematical model of a port power decoupling Power Router based on MMC-UCESS, and studied the top-down energy management strategy, including the rational allocation of power, power decoupling control, energy storage capacitor status determination and voltage balance control, DC bus voltage control and three-phase circulating current control. The operation mode of the Power Router and the method of using the UCESS to adjust the power flow pattern is discussed. Finally, a Matlab/Simulink simulation has been built to verify the proposed system.

ABSTRACT. Large-scale photovoltaic (PV) generation system connected to HVDC grid has many advantages compared to its counterpart of AC grid. DC connection can solve many problems that AC connection faces, such as the grid-connection and power transmission, and DC connection is the tendency. DC/DC converter as the most important device in the system, has become one of the hot spots recently. The paper proposes a centralized DC/DC converter which uses Boost Full Bridge Isolated DC/DC Converter(BFBIC) topology and combination through input parallel output series(IPOS) method to improve power capacity and output voltage to match with the HVDC grid voltage. Meanwhile it adopt input current sharing control strategy to realize input current and output voltage balance. A ±30kV/1MW system is modeled in MATLAB/SIMULINK and a downscaled ±10kV/200kW DC/DC converter platform is built to verify the proposed topology and control strategy.

ABSTRACT. A novel isolated high gain bidirectional DC/DC converter for the MVDC-connected PV power generation system is proposed in this digest. Basic configuration and operation characteristic is introduced. Circuit analysis and prototype circuit will be explained in the final paper.

ABSTRACT. In order to meet high voltage requirement, three-level structures are attractive. In this digest, a three-level dual active bridge for energy storage system in DC microgrid is investigated. An adaptive auxiliary inductor is proposed to extend the zero voltage switching in light load. The modulation trajectory is proposed. With the optimized modulation trajectory the conduction loss in the auxiliary inductor is improved. The simulation results is verified the modulation scheme.

ABSTRACT. In this paper, a novel three-port converter(TPC) for stand-alone photovoltaic(PV) power system application is proposed, and also presents the control strategy and power management of this converter. This converter uses three switches and switched capacitor structure to obtain a higher voltage gain and reduce the voltage stress of the switch. The control strategy can manage power flow reasonably and efficiently, which has been verified on a 400W prototype of the TPC.

ABSTRACT. The topology and operating principle of the asymmetrical double commutated cells (ADCC) MMC are clarified. A hybrid MMC which combines the ADCC and half-bridge cell is proposed. The dc fault blocking capability of the hybrid MMC is verified by MATLAB/Simulink simulation.

ABSTRACT. Aiming at the differential displacement sensor of the active bearing (AMB) system, the fault-tolerant control of the sensor probe is studied. The main form of the sensor probe fault and the modeling method of the fault sensor are analyzed. The characteristics and identification methods of the sensor of different forms are studied. Based on the part of the failure of the probe failure, proposed Discrete Fourier Transform(DFT) based on LabVIEW,through the Fourier transform of the output voltage of the controller and the sensor, observe the difference in phase difference, so as to determine which sensor failure.

ABSTRACT. Magnetic encoder based on giant magnetoresistance effect, also known as GMR-based magnetic encoder, has several distinct advantage over the traditional Hall-effect magnetic encoder such as its simpler structure, higher resolution and sensitivity as well as a better tolerance toward extreme working environment. This paper gives a detail design scheme of a GMR-based magnetic encoder. Finite element analysis (FEA) simulation is carried out to find the relationship between the thickness of the air gap and the size of the magnet. Hardware design and software configuration are also discussed. Finally, an encoder prototype is made and the experiment result proves the encoder’s feasibility in position detection of the motor control system.

ABSTRACT. To develop a new standard design, an electromagnetic-structural finite element analysis has been conducted considering the electromagnetic force generated in the gas-insulated bus(GIB) with a large current. The GIB are electrical busbar parts of a gas-insulated switchgear(GIS) installed in power plants and substations. Since the electromagnetic forces generated by such a large current flowing through inner conductors in the GIB tend to be very large, the structural integrity of the GIB should be evaluated. The magnetic force was calculated by the virtual work method and structural analysis was performed by utilizing the calculated force as a load condition. By modifying the designs based on the structural safety evaluation results, the maximum lengths of conductors could be increased by about 40~50%

ABSTRACT. By using the low mass density compaction, the electrical machine with soft magnetic composite (SMC) cores has shown its great advantage of the low manufacturing cost over that with silicon steels, especially in the mass production. For the laboratory prototype, wire cutting method is widely used to build the SMC cores for electrical machine. However, cutting the SMC perform block can destroy the magnetic properties of the SMC material, making that the electrical machine made in the laboratory cannot have the same performance as that in the mass production. To minimize the gap between the laboratory prototype and the mass production, the SMC cores should be made by the die compaction. However, to achieve high mass density, the compact pressure must be high and the productivity is low. On the other hand, low mass density compaction would greatly increase the productivity, but the core performance may deteriorate, which can be dealt with careful design and optimization of electrical machine. This paper presents our recent investigation on the manufacturing process of soft magnetic cores. The details of designing the die tools and building the SMC cores by using these tools are described.

ABSTRACT. Power transformers are one of the most important equipment in power substations and distribution systems. As its cost is about 55% of the whole substation cost, it can be called the valuable element in the power grid. Thus its lifetime management based on economical and technical indexes is highly essential for facilitating asset management and achieving more reliability in the power system. This study presents the factors that can affect transformer ageing, analyzes oil test parameters and performs dissolved gas analysis (DGA). Some existing methods for evaluating transformer operation based on DGA are compared. The pros and cons of each method are shown, and a simple method to assess the transformer condition is found. Also, three power transformers with real parameter values and oil samples are studied for the lifetime evaluation, and some possible solutions are proposed for better operation and optimized maintenance.

ABSTRACT. This paper proposes an innovative fast fault diagnosis (FFD) method for analyzing different fault cases and reconstructing the operation in the shortest possible time. Compared with established fault-tolerant methods, the new FFD method does not require complicated vector-tracking observer, while greatly improving the diagnosis speed. The presented simulation and experimental results verify the effectiveness of the proposed method and demonstrate its advantages during fast electro-mechanical transients over the established methods.

ABSTRACT. The concept of fault detection (FD) on Induction Motors (IM) is of ever increasing importance, because IMs, although rugged, cheap, reasonably portable, and high effective, are still liable to various sorts of undesirable faults with increase of maintenance costs. Much literature has been written on FD, but little has been said on the use of advanced pattern recognition methods for on-line classification of time-varying faults. Therefore, this paper presents a new method of diagnosis for on-line diagnosis based on a nonlinear curvilinear component analysis capable of detecting and follow the evolution of a fault in a phase.

The statistics available from IEEE and EPRI for motor faults [1, 2] claim that stator-winding faults contribute to as much as 26% of the total number of motor failures and are evolving. The stator winding faults begin as an inter-turn short circuit, which evolves over time into a short circuit between coils and phase windings. Thus it is fundamental that a diagnosis be made able to track them in real-time [3, 4].

The FD for stator winding faults is carried out by analysing the stator current spectrum and observing the changes with respect to the stator current spectrum of a healthy IM.

ABSTRACT. The influence of different fault modes (open-circuit fault and short-circuit fault) on the post-fault performance of six-phase fault tolerant permanent magnet synchronous motor (FTPMSM) is investigated in this paper. The copper loss of the FTPMSM under different fault modes is calculated in analytical form based on the heat equivalence principle due to the non-sinusoidal waveform of non-fault phase current. The iron loss of the FTPMSM under different fault modes are accurately calculated via the electromagnetic field finite element analysis. Furthermore, the thermal analysis based on the lumped-parameter thermal network is proposed for the FTPMSM, which is able to evaluate the post-fault performance of the six-phase FTPMSM under different fault modes. This paper can provide a guideline for engineers in the fault tolerant control design of the FTPMSM.

ABSTRACT. This paper studies the dynamic response of the wound rotor brushless doubly-fed generator (BDFG) in asymmetrical fault conditions. Physical behaviors under asymmetrical short-circuits are described by generalized analytical solutions and the relationship between flux linkage vectors is derived. The symmetrical components theory is applied to calculate the asymmetrical short-circuit current. Simulations by Simulink are carried out and results are compared with analytical calculations. The agreement of all results verifies the proposed analytical method in predicting the fault response of the BDFG.

ABSTRACT. Six-phase induction motor with double star winding shifted by 30° become bad in performance after stator one phase is open-circuited. In order to improve phase-deficient operation performance, a method of space vector pulse width modulation (SVPWM) with fault-tolerant ability is proposed. The star point of open-circuited winding group and the neutral point of inverter DC bus are interconnected; the 32 winding voltages corresponding to 32 inverter switch states are mapped to d-q plane and z1-z2 plane through a five-dimensional orthogonal matrix, and 32 basic vectors are obtained; the ten basic vectors located in d-q plane outer layer are selected to compose six intermediate vectors; the expected vector in d-q plane is synthesized by using intermediate vectors and zero vector. Experimental results show that the electromagnetic torque ripple and rotor speed ripple of proposed method with fault-tolerant ability are respectively 30% and 25% that of original method without fault-tolerant ability.

ABSTRACT. This article presents a method for control of a multiphase motor drive based on the use of a cognitive network that is capable of modelling nonlinearities of the system in fault conditions. To obtain a faithful model of the drive, a neural network (trained with the results of simulated faults) is used in the control algorithm in order to predict the system performance and adapt the control. A new multiphase motor with variable characteristics, particularly suited to applications in which a very wide variability of the speed field is required, will be described and presented in its structure. The technique to remedy failure adopted for this drive will be presented and described in its characteristics. The effectiveness of the control technique lastly will be highlighted by simulations that put it in comparison with classical solutions that employ PID controllers.

ABSTRACT. The shortcoming of permanent magnet (PM) machine is the de-excitation problem under fault condition, which is a main issue for aircraft application. Thus, modeling different kinds of faults accurately is of great importance. This paper presents the comparison of three different modeling methods dealing with stator winding open circuit (OC) fault and turn-to-turn short circuit (SC) fault. The modeling methods are field-circuit coupling model (FCCM) method, finite element analysis based electrical model (FEABEM) method and finite element analysis based mathematical model (FEABMM) method. The evaluation criteria are based on the accuracy of the methods and the simulation time. The simulation results show that the FEABMM method presents a high accuracy and relatively a shorter time.

ABSTRACT. With the rapid development of electric vehicles, fault tolerance requirements of the motor used in electric vehicles become higher and higher. Multi-phase permanent magnet synchronous motors (PMSM) with their low torque ripple and high reliability and other advantages gradually become the main choice of electric vehicle drive motor. In this paper, taken six-phase double Y-shift 30° windings PMSM as the object, compared with the traditional three-phase PMSM, the performance after one phase open is analyzed, and then in order to decrease the torque ripple after one phase open, a fault-tolerant method of adjusting the phase angle of the left phase current is presented. The finite element simulation results show that when one phase open, compared with the three-phase PMSM, the output torque ripple of the six-phase PMSM is lower, and the presented fault-tolerant method can decrease the torque ripple further.

ABSTRACT. A fault-tolerance control method for an open-winding multi-disc motor capable of being used in wide speed range applications is designed and introduced. The open-winding method is proven to be effective in field weakening to enhance high speed performance. But the dual inverter may increase the chance of hardware function failure. No additional hardware is required to realize the control method. By the way, it can be applied in the proposed multi-disc motor which could improve the reliability of system. The experiments waveform show that the system when system work the internal switch of the power module failure is work normally which proves the effectiveness of the proposed fault tolerance-control method.

ABSTRACT. This paper proposes a method for high-resistance connection (HRC) fault severity detection in a permanent magnet synchronous machine (PMSM). The proposed method is based on the zero sequence voltage component (ZSVC) and the stator currents. The HRC fault severity detection is achieved by solving a binary linear equation group about the additional resistance of each faulty phase. The simulation results show that the HRC fault severity can be effectively detected by the proposed method.

ABSTRACT. Much attention has been paid to Virtual Synchronous Control (VSynC) strategy for DFIG in aspects of mimicking the electromechanical behaviors of synchronous generators, yet neglecting the electromagnetic responses. This paper, for the first time, focuses on the electromagnetic transient behaviors of VSynC-based DFIG and proposes a voltage compensation VSynC strategy to implement LVRT during asymmetrical grid faults. The proposed strategy improves the inherent defect of existing VSynC strategy, capable of limiting the overcurrent in the rotor circuits and suppressing the oscillations of electromagnetic torque. Simulation results validate the effectiveness of the proposed strategy.

ABSTRACT. A new method for detecting broken rotor bar fault (BRB) in induction motors is proposed which is based on the combination of weighted subspace fitting (WSF) and bare-bones particle swarm optimization (BBPSO). In the circumstance of low signal-to-noise ratio and small snapshots data, WSF owns an excellent estimation performance, with a heavy computation. In order to improve the rapidity of WSF, BBPSO has been proposed to quickly search solutions of WSF. Performance of this new detection method is texted with the simulated stator current signal of an induction motor with rotor fault, providing the results that WSF-BBPSO can indeed identify accurately the frequencies multitudes and initial phase of the components and its estimation precision meet the ideal requirements. Finally, the related experiment on an induction motor is conducted and the results demonstrate that the WSF-BBPSO-based method to detect rotor fault in induction motor is effective even with short-time sample and in low SNR environment, meanwhile compared with FFT and ESPRIT-SAA method to prove its superiority and feasibility.

ABSTRACT. Stator inter-turn short circuit fault is one of the common faults in Double Fed Induction Generator (DFIG), the mathematical model of the DFIG is established based on the multi - loop theory, and the model of DFIG is built on the MATLAB / Simulink platform under normal condition and different degrees of inter - turn short circuit. The mathematical model of the grid side converter is analyzed to determine the corresponding control strategy, and the concrete given process of the PI regulator parameters is given. Through the simulation analysis of the DFIG under different conditions, the simulation results are consistent with the actual situation, which proves the feasibility of the control strategy. When the stator occurs turns short-circuit, the stator three-phase current is not symmetrical and its corresponding amplitude is increased, there is more obvious 90Hz specific frequency harmonics in rotor-side current FFT.

ABSTRACT. The paper focuses on the effect of Short Circuit Fault (SCF) in the upper switch of phase-A on electromagnetic field of PMSM. After this fault, DC components in three phase current are produced. Thus, the effect of the cocurrent pulsating magnetic field produced by DC components on air gap magnetic field is analyzed in detail. The obtained conclusions can provide useful reference for fault diagnosis.

ABSTRACT. Rotor winding interturn short circuit is the main fault of synchronous electric machines, it is of great significance to the safe and stable operation of the machine to discover and handle the fault timely. In view of this, the fault positioning method of rotor turn-to-turn short circuit of synchronous machines was studied. The mathematic expression of exciting magnetomotive force (e-m.m.f.), electromotiveforce (e.m.f.) and current of stator were deduced. we analyzed the characteristic harmonic of e-m.m.f., stator e.m.f. and current caused by rotor winding interturn short circuit; every harmonic amplitude variation of stator branch current was given in the relationship with rotor turn-to-turn short circuit. The different harmonic variation ratio of stator branch currents is only relevant to the position of the rotor interturn short-circuit coil and has a one-to-one relationship, so the rotor interturn short-circuit positioning method is presented. The method is verified by six-pole non-salient pole synchronous machines.

ABSTRACT. To solve zero-sequence current and harmonic wave problem of the semicontrolled open winding PMSG system, a model predictive current control (MPCC) method is proposed based on the analysis of the working principle of the semicontrolled open winding PMSG system and the generating mechanism of zero sequence current. This method can not only achieve the goal of suppressing zero sequence current, but also avoid PI current controllers parameters compare with vector control method. Finally, the simulation results validate effectiveness of proposed method.

ABSTRACT. This paper proposes a simplified model predictive control (MPC) for open-winding permanent magnet synchronous motor (OW-PMSM) system with two isolated power sources. According to the relationship between the torque and flux in PMSM, the two control constraints, torque and flux, in conventional MPC are converted into an equivalent flux vector, which eliminates the weighting factor in the cost function. In addition, in order to reduce the computational burden of the conventional MPC, an improved prediction algorithm and a novel voltage selection scheme are proposed to select the optimal voltage vector using twice evaluation. Simulation results are presented to prove the effectiveness of the proposed method.

ABSTRACT. Overload performance of permanent magnet motor is very important for some special occasions, which has been generally limited by temperature rise of stator. This paper introduces a new method based on heat storage of phase change paraffin to enhance the overload performance of motor. The heat variation of motor was analyzed under overload process, and the key affecting factors were given to control the temperature rise. According to the structure of permanent magnet motor, this paper analyzed the influence of cooling structure for phase change paraffin and given three cooler designs (pure paraffin, aluminum plate-fin and heat pipe cooler). The experiment models of cooler designs were built to verify the analysis.

ABSTRACT. Recently, redundancy permanent magnet synchronous motor (PMSM) is widely applied in aviation. To improve the reliability of redundancy PMSM, the short-circuit current should be restrained via anti-short-circuit design. For the further optimization design of redundancy PMSM, it is essential to research the influence of anti-short-circuit design on the PMSM performance. Therefore, in this paper, two dual-redundancy PMSMs are designed without and with anti-short-circuit design method. Then, via theoretical analysis and simulation, the performance differences between the two PMSMs are researched, such as back electromotive force, electromagnetic torque, stator core loss and dynamic performance. The results show that anti-short-circuit design degrades the electromagnetic torque and dynamic performance, and increases the stator core loss.

ABSTRACT. Two outer rotor PMSMs with different rotor topologies, surface-mounted permanent magnet (SPM) rotor and consequent-pole (CP) rotor are designed for in-wheel direct drive. A comparative study is presented on the characteristics of the two motors under two typical short-circuit faults, three-phase symmetrical short-circuit (SSC) fault and single-phase asymmetrical short-circuit (ASC) fault. The fault current, torque behavior and magnet demagnetization characteristics of the two motors are analyzed and compared in detail. Results show that the anti-demagnetization ability of CP rotor motor is much weaker than the SPM rotor even having a smaller fault current during the short-circuit faults.

ABSTRACT. The self–sensing magnetic bearing technology offers significant cost savings and the potential for dynamics advantages due to its fundamental sensor-actuator collocation. This paper proposes a rotor displacement self-sensing scheme for the permanent magnet bias magnetic bearings (PMB) using three-level amplifier demodulation. Based on the proposed structure of radial PMB, the self-sensing principle is presented by the magnetic circuit analysis. Then a mathematical expression which includes voltage of the coil, neutral point voltage of the coil and coil current is derived. Based on the derived formula, a practical self-sensing algorithm adapting for three-level switching power amplifier (PA) is proposed. In three-level switching PA, voltage of the coil is non-ideal at high level or low level because of inductive load. If signals are sampled at these non-ideal times, the detection precision becomes worse. The problem is solved through sampling at zero level and singular point will not appear. The experiment on a magnetically suspended motor show that this method can satisfy the performance demand of magnetic bearings system and the rotor speed can reach 3342 RPM.

ABSTRACT. Two linear hall sensors are utilized to detect the mover position of permanent magnet linear motor (PMLM) in this digest. To eliminate the harmonics of the sensor signals, suboptimal multiple fading Kalman filter (SMFEKF) is utilized. The third-order harmonic is considered into the observation model, and high-order harmonics are considered as observation noise. Compared with traditional EKF, SMFEKF shows higher robustness against model parameter mismatch. Experimental results show that the proposed method can completely eliminate the impact of harmonics when the motor is stationary and significantly improve the accuracy when the motor is running.

ABSTRACT. Sensorless vector control strategy based on sliding mode observer (SMO) was adopted in flux-switching permanent magnet machine (FSPM). The rotor position and speed estimation algorithm was obtained according to the mathematics model of FSPM. Further, the stability criterion was also put forward. At last, an FSPM prototype was designed and the sensorless control strategy was verified well by experiments.

ABSTRACT. Improving the detection accuracy of the speed and position of maglev train can effectively ameliorate the performance of train control system. Long primary segmented permanent magnet linear synchronous motor (LPSPMLSM) can be used in medium and low speed maglev train. In this paper, a high frequency pulsating voltage injection method is proposed for the LPSPMLSM, which is used to estimate the speed and position information of the motor. The effectiveness of the method is verified by simulation experiments.

ABSTRACT. Sensorless and torque control of Switched Reluctance Motors (SRMs) is a well researched field. Many techniques rely on the measurement of phase inductance which can be significantly affected by the mutual phase inductance. By measuring the mutual inductance, the accuracy of the sensorless and torque control techniques can be improved. This paper presents two novel techniques which profile the mutual inductance without an offline calibration technique. The techniques are developed for three-phase type SRMs.

ABSTRACT. This paper presents a sensorless control method for IPMSMS drives over a wide speed range operation, including zero speed by using current derivative measurements during each PWM period. The rotor position estimation is based on relating the measured current derivatives which arise from fundamental PWM voltages to the machine with the incremental inductance. Compared to other saliency tracking sensorless control schemes, this method doesn’t require additional injected signals or test vectors. The experimental results are shown to verify the effectiveness of this sensorless control for IPMSM.

ABSTRACT. Abstract — Sensorless control can be utilized to reduce cost, size and total complexity of a motor drive or enhance reliability of the system. This paper first presents a sensorless control algorithm for a surface permanent-magnet synchronous motor (SPMSM) based on estimated flux linkages and stator currents. Within the algorithm, rotor position error can be predicted by comparing the estimated currents with measured stator currents. Performance of the sensorless control based on flux-linkages and the dependency of the algorithm on motor parameters is then numerically investigated via simulations. It is found from the investigation that the accuracy of the method depends on the motor working condition, and it can be improved by parameter estimation.

Index Terms – sensorless control, surface permanent magnet synchronous machine, flux-linkage based method, rotor position estimation.

ABSTRACT. In order to solve the difficulty of measuring the speed and the position of maglev permanent magnet linear synchronous motor (PMLSM),a sensor-less back-electromotive force (EMF) -based sliding mode is proposed.And for the drawback of the sliding mode technique called chattering phenomenon,a series of improvements are provided.

ABSTRACT. In order to improve the performance of the high-speed PMSM control system, a sensorless DPC (Direct Power Control) scheme for pump-kind applications is proposed. For further improve the performance, a high precision rotor position estimation, which is the key factor for the DPC scheme, is proposed. The experimental results validate effectiveness of the proposed method.

ABSTRACT. This paper presents a rotor position estimation method of a five-phase IPM motor based on high-frequency sinusoidal voltage injection to improve the sensorless control system performance at low speed. The high-frequency sinusoidal voltage is injected into the estimated rotor reference frame. The estimated rotor position and speed are obtained by detecting and processing high-frequency current response of the stator. Simulation results show that this method has good tracking performance with stable and effective operation at low speed and even zero speed.

ABSTRACT. Resonance occurs in the uncontrolled slave motor at the middle and lower speed due to the electromotive force and stator resistance error between the two motors when two PMSMs drive in parallel in SIMM structure with master and slave control method. This paper proposes that a notch filter with pole-zero cancellation method to avoid resonant bands and lead controller to reduce pulsation is proposed for stable parallel operation based on resonant analysis of frequency response of mathematical model of SIMM system. The proposed method verified with simulation.

ABSTRACT. This paper presents a parameters self-turning fuzzy control of magnetic levitation system of controllable excitation linear synchronous motor magnetic suspension feeding platform. Magnetic levitation system is an important subsystem of magnetic suspension feeding platform, which is highly nonlinear, inherently unstable,strongly coupled and highly sensitive to initial condition.In view of the above characteristics,id=0 control mode was used to minimize the impact of magnetic coupling phenomenon of linear synchronous motor on the suspension system. Electromagnetic force between field excitation and mover core is taken as the controllable levitation force, and the other part of the normal force is taken as disturbance of the suspension system. A parameters self-turning fuzzy controller is designed to control maglev system, which includes main fuzzy control unit and fuzzy parameter optimization unit. Simulation results with different initial conditions reveal that the proposed control scheme stabilized the system.

ABSTRACT. The method sensing the phase current using three shunt resistor cannot perform the sensorless control since there is the area that cannot measure three phase current especially in high-speed motor operation where the MI(Modulation index) is increased. In this paper, the boundary where phase currents cannot be obtained is defined and the method for reconstructing the phase current is proposed by predicting phase current in the area which phases current measurement is impossible. Also, the EMF observer and synchronous voltage recalculation method are applied for sensorless control considering both linear area and over-modulated area.

ABSTRACT. in order to improve performance of switched reluctance motor (SRM) at high speed, a new hybrid asymmetric and buck-boost fronted converter for SRM with active boost voltage capability is proposed. Different from existing converters with boosting voltage, the proposed converter has an active regulation ability of boosting voltage, in which voltage level is independent from switching and dwell angels. Firstly, the basic structure and operating modes are introduced and analyzed. Secondly, the key parameter such as inductor and boosting capacitor is investigated and designed. Finally, some experiments are implemented and results show the validation of proposed method

ABSTRACT. To enhance the control precision of permanent magnet synchronous motor (PMSM) under parameter variations and load torque disturbances, a minimal reduced-order load torque observer (MRLTO) based discrete-time sliding mode control (DSMC) scheme is presented. First, a DSMC controller is presented on the basis of the second-order discrete-time PMSM dynamics model to enhance the speed tracking response and robustness. Then, a self-tuning switching gain and the saturation function are introduced to suppress the chattering. Moreover, to simplify the implementation and further enhance the robustness against the disturbance of PMSM, a minimal reduced-order load torque observer is presented, which can provide accurate estimation and feed-forward compensation of the load disturbance. Stability of DSMC and MRLTO is analyzed, respectively. Simulation and experimental comparisons demonstrate the presented controller is superior.

ABSTRACT. This paper proposes a novel control strategy for the brushless DC motor drive system fed by electrolytic capacitor-less inverter. In order to obtain high power factor, this paper proposes a new control method that regulates the inverter input current. The calculated compensation current of small film capacitor is subtracted from the ideal ac input current, which is regarded as the ideal inverter input current. The inverter input current is regulated by a PI controller, and the output of PI controller is used as duty-cycle of PWM technique. Meanwhile, the PWM_ON_PWM pattern is used in the proposed system, which can reduce the torque ripple in BLDCM. The effectiveness of the proposed system has been verified by simulation and experiment.

ABSTRACT. In this paper, a novel boost chopper converter-based torque sharing function (TSF) control strategy for switched reluctance motors (SRMs) is proposed to reduce the torque ripple. Due to the advantages of the simple structure, low cost, high reliability and wide speed range, SRMs have attracted much attention in the industrial applications. However, the torque ripple is one critical issue to restrict the further development for SRMs, which is mainly caused by the doubly salient motor structure and unbalanced electromagnetic torque during the commutation region. Though the torque ripple can be reduced by employing the TSF control scheme, the incoming phase torque still cannot achieve its torque reference perfectly and the outgoing phase torque cannot drop down to its reference quickly in the commutation region. Therefore, a boost chopper circuit is presented to combine with the conventional asymmetrical half-bridge converter for TSF control, which effectively minimizes the torque ripple by the enhanced bus voltage. The effectiveness of the proposed scheme is verified by the simulation on a 150 W, four-phase 8/6-pole SRM.

ABSTRACT. In this paper, a 5kW novel multistage axial-flux permanent magnet machine (M-AFPM) is analyzed. As a key part of the machine, stator core of silicon steel and SMC are studied by 3D finite element method (FEM) respectively. No-load, full-load, magnetic field distribution, core loss, etc. are calculated. FEM result indicates that SMC-materials have almost equal influence on EMF, magnetic field distribution and electromagnetic torque. But in aspect of core loss, Differences appears between silicon steel and SMC. The FEM result is also verified by the test results of the prototypes.

ABSTRACT. In this paper, a new control scheme is proposed for the multiple-channel indirect matrix converter (IMC) fed dual three-phase PMSM machine based on vector space decomposition (VSD). With VSD, the torque of multiple channels can be controlled as a whole. By designing space vector modulation (SVM) of VSI under non-constant dc-link voltage and safe commutation strategy with CSR, good operating performances are provided for the drive. Besides, the active damping is proposed to improve harmonic performance on grid side. Both simulation and experiments are given to verify the validity of the proposed strategy.

ABSTRACT. In this article, small-signal modeling of Virtual Synchronous Generator (VSG) is carried out, and complete the steady-state analysis and sensitivity analysis. Each sub-module is modeled in state-space form. Then the model is combined to get the entire inverter model, which can be analyzed comprehensively. The system analysis can guide the selection of parameters. Finally, simulation verify the accuracy of small signal modeling by Simulink.

ABSTRACT. With the development of more/all electric aircrafts, variable frequency AC (VFAC) generation system becomes popular. Dual stator-winding induction generators (DWIG) utilized in VFAC systems have the feature of high fundamental frequency. However, the switching frequency of high power devices does not exceed 5 kHz in general, which makes carrier ratio lower. Thus, how to ensure the quality of system’s output voltage under low carrier ratio condition becomes the focus of the study. In this paper, a novel low carrier ratio control method is proposed to improve the quality of output voltage. In this method, selective harmonic elimination pulsewidth modulation (SHEPWM) is adopted and carrier ratio changes depending on different fundamental frequency range. The switching losses are limited while the quality of the output voltage remains good. Simulation and experimental results prove this method is effective.

ABSTRACT. In this paper the Parameters of a Double Layer Super Capacitor Bank are experimentally identified using Recursive Least Squares (RLS). In order to construct the Ax = B matrix for RLS, the SC charge/discharge data is pre-processed using a Low Pass Filter and Differentiators. Results have been verified with a shortened Zubieta technique corresponding to the 2-branch model. Results show similar characteristics signaling that the parameters are correct.

ABSTRACT. This paper provides an overview of battery storage devices, including the most recent technologies, acceptable for AC microgrid applications. The corresponding control schemes for battery storage inverters are also discussed. The paper details a specific control scheme for a battery storage inverter, compatible with a decentralized AC microgrid architecture recently proposed by the authors. Simulation results included so far illustrate advantages of the proposed control scheme and of the entire AC microgrid architecture. Full paper will include more detailed simulation results corresponding to different load types under various microgrid conditions.

ABSTRACT. This paper proposed a method of hybrid energy storage configuration to determine the value of capacity and the value of energy particularly for energy storage systems in an industrial estate.The purpose of the method is to effectively reduce randomness and volatility of PV output, to delay distribution network upgrade and expansion, and to improve economics of energy storage.

ABSTRACT. In this paper, considering the change rate of the load, a frequency division control is optimized to improve the control accuracy of hybrid energy storage, compared to the traditional frequency division control. Firstly, the optimal control strategy is designed based on the first power allocation and the second power allocation. Secondly, the model is applied in residential area to avoid the peak load through simulation. The simulation results are in agreement with the theoretical analysis, which verifies the correctness of the control strategy.

ABSTRACT. In order to increase the efficiency of enterprise and reduce the grid load demand of large-scale renewable energy such as wind and solar energy in regional power grid system, Shapley value method has been proposed to analyze the cooperation game relationship between high energy-consuming customer and power system. Using the system dynamics method, an interaction analysis model for describing participation of high energy-consuming customer with power system under certain regional economic has been established. The simulation results showed that high energy-consuming customer play an significant role in improving the capacity factor of renewable energy in power grid within short period. Concerning the price compensate strategy of government, policy guiding suggestion of improving renewable energy consuming has been proposed. Based on production market quotation, excitation policy of peak regulation with user participation will facilitate the development of renewable energy effectively. However, for the long-term planning, policy of regulation and control on renewable energy should be schemed to avoid wasting of resource and overheating of investment.

ABSTRACT. The combination of the energy storage system and the distributed photovoltaic (PV) system can provide significant functions, such as power smoothing, grid connecting, and peak shaving for the photovoltaic system. This paper focuses on crucial problems of operating PV /energy storage generation system, and introduces some key techniques of designing the energy storage container, the energy storage bi-directional converter, the energy storage battery management, the energy storage generation monitoring system, and the energy management system of the PV /energy storage power system. Further, the proposed solutions are verified in demonstration projects.

ABSTRACT. In this paper, we examined the utility of as electric vehicle(EV) and power storage system in micro grid system that introducing solor power generation(PV). In recent years, EV have attracted attention not only from a transportation point of view, but also from the viewpoint of its utility as a domestic power storage system. Therefore, the introduction of a power storage system has been studied in the scenario that many distributed power sources are introduced to the system. Thereby, EV is studied not only for a transfer but also as a power storage system because it is further expected to enhance the value when EV can be used as a power storage device.

ABSTRACT. Considerations for Sizing Energy Storage Technologies in Wave Energy Systems

ABSTRACT. Lead-carbon Batteries as an energy storage device, its state of charge is an important parameter of the entire battery energy storage system. This paper uses the Improved Thevenin model as the battery mathematical model, and establishes the state-space equations. First of all, it fits the function relationships between the parameters and the SOC. And then it establishes a set of equations combined with the electrical characteristics of the model. Finally it searches out the best parameter estimation according with unconstrained nonlinear optimization methods. It simulates the battery performance very well to use the Battery mathematical models and parameters, the error within 1%.This paper uses Kalman filter based on the wavelet transform estimation method to estimate the SOC, and it finally verifies this estimation method has a high accuracy of estimation, the error within 2%.

ABSTRACT. This paper examines how changing the magnetic orientation of permanent magnets in interior permanent magnet synchronous motors (IPMSMs) affects their demagnetization resistance. A prototype that consists of a 130-degree V-shaped rotor core in which parallelogram magnets with oblique orientation are arranged is evaluated for demagnetization at 180ºC. It is confirmed that the greater the magnetic field orientation angle α, the higher the demagnetization resistance.

ABSTRACT. In this paper, the torque production mechanisms of integral slot distributed, fractional slot concentrated winding (FSCW) and Vernier permanent magnet synchronous machines (PMSMs) are firstly investigated together from the perspective of magnetic gearing effect. The torque contribution and magnetic gearing effect in eight 12-slot PMSMs with different rotor pole numbers are analyzed and compared. The study in this paper not only provides an insight into the torque production mechanism of the electrical machines of different types, but also creates a unified criterion for comparison between different kinds of PMSMs.

ABSTRACT. A novel flat linear switched reluctance motor with doubly-excited windings is presented in this paper. It helps to increase the electromagnetic force by means of mover excitation cooperate with stator excitation. The concept design and operating principle are presented. The electromagnetic force is formulated analytically based on equivalent magnetic circuits, and the result is validated by numerical analysis. It shows that the machine can achieve high thrust force compared with conventional linear switched reluctance machines. Furthermore, the installation of windings on both stator and mover can make the structure more compact and increase the system force density.

ABSTRACT. This paper presents a method to calculate the core losses in SiFe laminations under magnetizations with DC bias and harmonics. DC bias is usually generated by the ground return current of high voltage direct current (HVDC) system intrude into the windings of neutral-grounded transformers, which leads to increase of harmonics and core losses. For accurate calculation of core losses under DC bias, the Jiles-Atherton (J-A) dynamic hysteresis model is incorporated into the finite element method. The J-A dynamic hysteresis model is constructed by combining the traditional J-A hysteresis model with the models of instantaneous eddy current and excess losses. To take the DC flux into consideration, the J-A dynamic model was modified by adjusting the parameters of instantaneous excess loss model. The theoretical results are compared with the measured results by a Single-Sheet Tester (SST 500), and it is demonstrated that the proposed methods is accurate and effective.

ABSTRACT. Low switching frequency operation is one of the most effective methods to reduce the switch losses in high-power industrial machine drives. However, a low switching frequency would affect the operation performance, e.g., harmonic distortion in the stator current, modulation delay and so on. With an electrically excited synchronous machine (EESM) being taken as the high-power drive load of a two-level inverter, this paper presents a novel pulse pattern based on the combination of model predictive control and sliding discrete fourier transform (SDFT) to cope with the low switch losses issues. Experimental results verify that this kind of pulse pattern could realize a similar characteristic with the selective harmonic elimination along with a dynamic regulation.

ABSTRACT. This paper presents a novel speed-power control scheme of a high speed BLDC(Blushless DC) motor for a blender machine. In order to improve efficiency and reduce noise and vibration, a conventional universal motor is replaced by BLDC motor and power control scheme for improve grinding performance of blender machine is proposed. The proposed speed-power control scheme prevents problems due to sudden load or vibration caused by material grinding in high speed region.

ABSTRACT. Calculation and matching of the main parameters of a brushless DC (BLDC) motor for a Battery electric vehicle (EV) is studied in this paper. Usually, different shapes of permanent magnet (PM) and different magnetizing methods will affect the performance of the motor. Especially when the motor is designed for an EV, more elements need to be considered, such as efficiency under normal operating conditions and torque ripple. So in this paper the performance of PMs with different shapes and different magnetizing methods will be compared by finite element analysis (FEA). Finally, the structure of the stator and rotor will also be optimized to obtain the required prototype model.

ABSTRACT. The skewed brushless DC motor adopted the Halbach array for improving electromagnetic torque. The paper analytical calculated the open circuit field and the armature winding field in the motor with Halbach array. The Halbach arrays have two types, one is each pole with two segments of magnet(1P2s) and another is each pole with three segments of magnet(1P3s). The electromagnetic torque is calculated by integrating the Maxwell stress tensor inside the air gap based on the open circuit field and armature winding field. Then, the Halbach arrays are optimized using the analytical method in order to improve the electromagnetic torque. The torque measurement and the finite element method verified the correctness of the torque analytical calculation.

ABSTRACT. The back EMF coefficient of the brushless DC motor is calculated from the average value of back EMF during conduction region. And the torque coefficient is gotten from the ratio of average torque and average current. Speed-torque characteristics expression of BLDC motor with unideal back EMF is obtained from the new back EMF coefficient and torque coefficient. Simulation and experimental results show this method can precisely meet the real speed-torque characteristics.

ABSTRACT. This paper presents the design and implementation of a high speed sensorless brushless DC motor (BLDCM) drive with commutation compensation. The back electromotive force (EMF) detection using three phase terminal voltage is implemented to detect the rotor position, in order to filter the high frequency switching signals, a low pass filter is applied in the back EMF detection circuits, which leads to a position detection error related to the motor speed. Thus, the proposed control method is aimed to correct the commutation instant with an angle compensation. The experiment results showed that this method has excellent performances with large load disturbance in a wide speed range.

ABSTRACT. Predicting a localized defect on a rolling bearing during the degradation process before a complete failure is crucial to prevent system failures, unscheduled downtimes and substantial loss of productivity. During this process, impulses associated with the fault are weak, nonstationary or time-frequency varying, and contaminated by noises, which render the problem of extracting these impulses very difficult. This work investigates the effectiveness of common signal processing techniques on predicting incipient faults, e.g. Fast Fourier transform, Short-Time Fourier transform, Wavelet transform. It was found that an adaptive filter is required to enhance and reconstruct the signals during the degradation process, and a combination of adaptive filter and Morlet wavelet transform is necessary in order to effectively detect a localized defect on rolling element bearings during degradation. The proposed method was applied to analyze vibration signals collected from a run-to-failure test of drivetrain. The analysis shows that the frequency associated with a bearing defect can be well identified in the early stage or during degradation

ABSTRACT. permanent magnet synchronous machines (PMSMs) equipped with dual three-phase (DTP) fractional-slot overlapping windings (FSOWs) are characterized by stator modularization, low rotor losses and easy manufacturing. However, the overlapping between the adjacent phase windings may cause poor magnetic insulation in PMSMs, which is undesirable in fault-tolerant applications. This paper proposes a type of novel stator structure, in which flux barriers are inserted in stator yokes of PMSMs to realize low mutual inductance between the adjacent phase windings in DTP FSOWs. The proposed stator structure is described in detail, and the principle of depressing the mutual coupling between the adjacent phase windings is also explained. In addition, the main electromagnetic characteristics of a 24-slot 14-pole DTP FSOW PMSM employing the proposed stator structure with flux barriers are compared with those of the counterparts using the conventional stators without flux barriers.

ABSTRACT. Wind turbine pitch systems are reported to be among the components with frequent failures. While the pitch systems are easily replaceable in onshore wind turbines, they result in expensive maintenance measures in offshore. This article presents an approach for health assessment of induction motor drives in pitch systems based on selected features derived from motor three phase currents. The features are calculated at wind turbine level and if fault is detected, they are transmitted to a central support vector classifier for accurate fault classification.

ABSTRACT. In this paper, we present the performance of massively parallel processing in finite element electromagnetic field analyses with time periodic explicit error correction. The Domain decomposition technique is used for parallelization, and the Message Passing Interface (MPI) library is used for processing communications. The numerical results indicate over a 64-fold speed increase compared with the sequential solver, and that it is very effective for designing electric machines and apparatus in a brief period of time.

ABSTRACT. A new method for rotor fault detection of induction motor is proposed based on the combination of Duffing and PSO(Particle Swarm Optimization) algorithm. The fault characteristic frequency can be extracted accurately by using the sensitivity of the Duffing system to the initial parameters.Based on that, this paper presents an PSO algorithm to calculate the amplitude and initial phase of each frequency component. The simulation and experiment results show that the proposed method can detect the rotor faults of induction motor quickly and accurately.

ABSTRACT. Traditional PI controllers can have poor regulation performance due to steady state errors when tracking sinusoidal signals. Hence synchronous PI controllers are often used, although this controller requires reference frame transformations. In this paper, a modified PI controller, which uses current feedforward, is developed to control the output currents of a matrix converter. The controller is implemented in the natural frame (abc) together with space vector modulation. The output current is then controlled. This controller does not require any frame transformation and it demonstrates improved steady-state tracking performance. The total harmonic distortion is improved at the same time. A constant switching frequency is maintained because of the application of the modulation stage. Simulation results verify the feasibility and effectiveness of the proposed controller.

ABSTRACT. The matrix converter has emerged as a direct AC/AC converter and has attracted research attention. This work proposes a Proportional Resonant (PR) controller based on the Space Vector Modulation (SVM) method for the three-phase direct matrix converter and its application systems. The PR controller, compared with the widely used PI controller, has better steady-state error performance, specific harmonics compensation capability, and the ability to handle sinusoidal quantities. These enhance the tracking performance of the converters and benefit the current quality improvement and selective harmonics suppression. The PR controller can be implemented in the natural frame in a straightforward manner, which removes the frame transformations involved in the stationary (αβ) and synchronous (dq) reference frame based control strategies. This alleviates the computation burden. Simulation results verify the effectiveness of the proposed PR controller for the matrix converter applications.

ABSTRACT. Energy Router is concerned in a lot of applications due to its powerful functionality and great flexibility. Strategy of capacitor charging plays a key role in the operation of energy router. This paper focuses on the submodule applied in the hybrid multilevel energy routers. In a submodule, two DC-links exist on both sides of the high frequency transformer and a three terminal DC-link is applied in the primary side because of three-level topology. These situations bring the complexity of the startup process. This paper proposes a startup strategy for a single submodule with the key feature of constant peak transformer current, which performs well between peak charging current and charging time. In the energy router, all submodules have identical structure and share the same strategy. The principle, process stages and verification are presented.

ABSTRACT. The paper proposed a new topology of Power Electronic Transformer (PET) in application of medium and high voltage 3-phase AC distribution network. The proposed topology has voltage self-balancing capability of DC bus capacitor and relatively small volume compared to other topologies. The control strategy and stimulation results are given to prove the feasibility of the topology.

ABSTRACT. A hybrid railway power conditioner (HRPC) is developed based on chopper cell modular multilevel converter (MMC) with four legs. The HRPC is able to compensate unbalance currents and reactive power. Its operational voltage at one phase is much lower than the voltage of the railway supply system. As a result, this phase of the MMC is connected to the 27.5kV bus without coupling transformer. The application of the MMC to the HRPC also brings the benefits of lower current distortion, removing extra filtering capacitor as well as better expansion and flexibility. The circulating current control of the MMC is studied in detail since bulky active power is transferred from one phase to the other phase in the back-to-back MMC. The cell voltage balance control is modified accordingly. Simulation results are provided to show the validity of the HRPC and its control.

ABSTRACT. This paper presents an improved single phase seven-level active rectifier architecture controlled by finite control set model predictive control (FCS-MPC). The FCS-MPC is designed to enable step up and step down power conversion with a unity power factor and generate seven level voltage waveform at the input. The proposed active rectifier architecture reduces harmonic contents of the rectifier input current by producing different voltage levels at the rectifier input. Owing to the architecture and multilevel operation, it reduces the EMI filter size, input current harmonic, the voltage rating on devices and switching losses that are lower than those of conventional three-level level rectifier topologies. Extensive simulation results are presented to verify the proposed converter when the load changes, the reference dc output voltage changes, and the grid voltage drops.

ABSTRACT. Operating characteristics of a large-scale wind farm consisting of series-connected outputs of thyristor rectifiers with wind generators and a current source thyristor inverter are simulated. Instantaneous voltage and current waveforms of wind generators and thyristor rectifiers are discussed when considering wind speed distribution.

ABSTRACT. This paper proposes a reactive power coordination control scheme combines doubly fed induction generator (DFIG) with static synchronous compensator (STATCOM) on the basis of considering the limited reactive power of DFIG. It takes the voltage stability of point of common coupling (PCC) as the target to determine the required reactive power value, which is a priority to select DFIG to compensate reactive power, and the surplus reactive power demand is supplemented by STATCOM. The reactive power regulation of DFIG needs to be realized by controlling the rotor side converter (RSC) and the grid side converter (GSC). This method not only can make full use of the reactive power regulation of DFIG itself, but also can reduce the capacity of reactive power compensation device. Simulation results based on matlab/simulink verify the effectiveness and superiority of the proposed scheme.

ABSTRACT. In recent years, environmental problems are being serious and renewable energy has attracted attention as their solutions. However, the electricity generation using the renewable energy has a demerit that the output becomes unstable because of intermittent characteristics such as variations of wind speed or solar radiation intensity. Therefore, it can cause frequency fluctuations or voltage fluctuations in the power system. Various methods have been investigated and reported so far to control the frequency and voltage fluctuations. This paper presents a new control method to suppress the frequency fluctuations occurring due to a large amount of photovoltaic (PV) power generation and wind power generation, which is based on power flow control of High Voltage Direct Current (HVDC) interconnection line and using a dead band in its frequency control system.

ABSTRACT. The stochastic nature of wind power generators and their possible outage are crucial issues which make them having difficulty to participate in electricity markets. However, demand side as a decent balancing resource can be used to compensate the challenges of lack of supply-demand balance or state of outage for wind generators. This paper firstly models the outage of wind generators. Then an offering strategy with a three-stage stochastic programming is presented for a hybrid power plant which includes a wind power producer and a demand response provider. Three electricity markets are considered including day-ahead, adjustment and balancing market. The conditional value-at-risk is also added to the offering strategy to control the profit risk. The offering strategy is tested in a wind farm and electricity market located in Spain. The result shows that the hybrid power plant offering strategy can effectively assist with the balancing and outage problem of the wind power producer and increase the overall profit of the joint operation.

ABSTRACT. The wake effects between wind turbines (WTs) inside a wind farm (WF) will reduced the overall captured power and the power flow inside the wind farm will cause electrical loss in the electrical devices. Proper active power and reactive power dispatch strategies, which control the power flow inside the wind farm, can reduce the electrical loss in the wind farm. In this paper, a coordinated active power and reactive power dispatch strategy is proposed to reduce the energy loss caused by wake effect and electrical loss caused by power flow and increase the power output of a Doubly Fed Induction Generator (DFIG) based wind farm. The strategy also coordinates the dispatch strategies at the WF level and the WT level. The active power reference and reactive power reference of each WT are chosen as the optimization variables and an adaptive partial swarm optimizing (APSO) algorithm is used for solving the problem. The proposed strategy is compared with traditional strategies in a designed WF. Simulation results show the effectiveness of the proposed strategy.

ABSTRACT. Sub-Synchronous Control Interaction (SSCI) is new sub-synchronous oscillation phenomenon caused by wind turbine controller. Its oscillation frequency and attenuation rate completely depend on the structure parameters of wind power converter and power transmission system. Therefore, in this paper, by means of electric circuit models, the physical nature of Proportional-Integral(PI) controller for wind power convertor are researched in detail, on the basis of the wind power converters are equally considered as amplifiers. And then, a new equivalent circuit model of wind power converter was builded. By using of this new convertor model, the equivalent impedance model of doubly-fed induction generator(DFIG)series compensated system is established, combined with models of DFIG and series compensation transmission system. Furthermore, the impedance scanning method is used to analysis mechanism of SSCI deeply, which reveals the converter control affect damping of sub-synchronous oscillation. Finally, the impacts of SSCI on torsional vibrations(TV) in drive train of wind turbine are also researched.

ABSTRACT. This paper proposes a novel rotor position detection Method of permanent magnet synchronous motor (PMSM) based on MEMS inertial sensor, where the MEMS inertial sensor is installed on the shaft of rotor. Firstly, the principle of detecting the rotor position by MEMS inertial sensor is illustrated. Then, in order to avoid the integral error caused by gyroscope, the multi-sensor information fusion scheme based on Kalman filter is proposed for detecting the rotor position when the motor is running. The effectiveness of the proposed method is verified by the experimental results on a 15KW PMSM motor prototype, which show the position detected by MEMS inertial sensor track the actual position accurately.

ABSTRACT. Abstract— In view of the direct torque control (DTC) with flux recognition accuracy problem for a bearingless induction motor, a super-twisting mode observer based on model reference adaptation system (MRAS) is proposed. Super-twisting (ST) instead of the voltage of rotor flux model is used in the speed sensoorless. In addition, the torque resistance change will bring speed identification error, through establishing adaptive torque resistance to modify rotating torque resistance on-line identification. Simulation shows that the speed sensorless based on super- twisting of MRAS not only can estimate rotor flux more accurate and have wide speed regulating scope, but also have higher robustness to the change of torque resistance parameters.

ABSTRACT. Aiming at the application of fan, pump and compressor load, a cost-effective sensorless drive control system of permanent magnet synchronous motor (PMSM) based on V/f control is proposed and realized in this paper. Aiming at the problem that conventional V/f control cannot maintain the stable operation in middle and high frequency domain and the load fluctuation, a method of adding the speed stabilizing loop is proposed. A method of extracting the perturbation component of the active power to compensate the given frequency is used to solve the problem. Perturbed active power is obtained by using the first-order high-pass filter to filter the input active power of the motor, and then the negative feedback for a given electrical frequency is realized. Simulation and experiment results show that the method has good adaptability and robustness to the load change, and verify the correctness and feasibility of the control method.

ABSTRACT. This paper presents a novel control strategy to reduce the DC-link voltage ripple for electrolytic capacitor-less PMSM drive system. By injecting the 3rd harmonic current into the driver system, the instantaneous power balance between the grid output power and the motor output power is achieved, so the DC-link voltage ripple is reduced obviously. For further improving the PMSM performance under DC-link voltage ripple, the repetitive control (RC) is introduced in the speed control loop of the space vector control. In addition, the input power factor can reach 0.95 and the harmonic of grid current are lower than the requirement of EN61000-3-2.

ABSTRACT. Model predictive direct power control (MPDPC) has been widely studied for the control of doubly fed induction generator (DFIG) under ideal grid voltages. However, conventional MPDPC presents highly distorted stator/rotor currents and high power ripples. This paper proposes an improved MPDPC by using a new definition of reactive power, which eliminates the sequence extraction of stator voltage and/or currents. The steady state performance is further improved by applying two voltage vectors during one control period and their duration are obtained based on the principle of power error minimization. Both Simulation and experimental results confirm the effectiveness of the proposed method.

ABSTRACT. This paper presents a novel method for improving utilization ratio of power supply used in the variable frequency controlling system of permanent magnet synchronous motor (PMSM), which has a high quality output waveform and can be used in a wide frequency range. Compared with the general variable frequency technique, which has 80% of the utilization rate only, the utilization rate of power supply introduced here can reach 100%. Both theoretic analysis and simulation results show that the proposed method is feasible to be used in the driving system of PMSM

ABSTRACT. In this paper, control system and simulation of an arc-linear permanent-magnet synchronous machine with normal armature windings and compensation windings are researched. Considering the special structure of the machine, the mathematical model of the machine is investigated and established. The control scheme and the control system for the machine are also researched to reduce the torque ripple for travelling smoothly. Moreover, the machine and the system are co-simulated within the closed-loop control system to validate the feasibility of the control scheme. To accelerate the process of simulation, simulation based on mathematical model of the machine is also researched. Compared with the results obtained by co-simulation, the feasibility of the mathematical model and simulation model of the machine are verified, and the effect and the feasibility of the control scheme and the control system for torque ripple suppression and smooth travel motion are further validated with faster simulation speed.

ABSTRACT. most of magnetic encoder ICs are on-axis, and they are generally suitable for inner rotor PMSM, sometimes used in external rotor PMSM. However, in some special occasions, these ICs are not used for the difficulty of mounting, for example, there is an external rotor PMSM with a hollow shaft, which is convenient for passing the control wire. It is difficult to mount these encoder ICs, because there is no axis. This paper proposes a novel combined magnetic encoder to solve the problem using AS5304 and SG211V.

ABSTRACT. Permanent Magnet Synchronous Motors(PMSMs) operating among wide speed range needs optimal flux-weakening method to reach to higher speed level. For motors whose critical point locates within the current limit circle, two different flux-weakening algorithms are discussed comparatively in this paper. One is the traditional feedback flux-weakening control strategy, the other is a revised feedback flux-weakening method with the Maximum Torque per Volt(MTPV) control in high speed level.Relative simulation has been implemented and the results prove that, compared with the traditional method, the revised strategy with MTPV control could produce a slight larger torque in high speed and widen the speed range with a fixed load torque.

ABSTRACT. This paper presented an integral sliding mode control based on speed regulation for permanent magnet synchronous machine (PMSM) single-current regulation (SCR) algorithm. In contrast to conventional PI control, the proposed sliding mode control not only contribute to the fast dynamic response to the variation of load level and DC bus voltage, but also effectively eliminates the steady-state error in the flux-weakening region. Combined with the SCR algorithm, the proposed sliding mode controller automatically generates both the flux-weakening magnetic current component under different speed operating conditions, and torque current component based on the crossing-coupling effects between d- and q-axes. The feasibility of the proposed controller can be verified by computer simulations and analysis.

ABSTRACT. Monitoring of diesel generators is an important part of the management program of electricity utilities. A reliable remote monitoring method over the on-site method is always desirable so that managing of time and resources can take place as efficiently as possible. This paper looks into solving the issue of on-site monitoring and control of diesel generators using readily available resources which are also cheap to setup and maintain. The work is investigated using the platform of Internet of Things (IoT) which is a very versatile technology in regards to the digital age in terms of interacting with environment and things. This paper looks into exploring the monitoring and control of generator using the power of IoT paradigm.

ABSTRACT. The mathematical models of the permanent magnet synchronous motor (PMSM) are complex systems, characterized by high coupling, onlinearity, parameter variation and they are highly influenced by disturbances.Conventional PID control method cannot make the system set value tracking and interference suppression both in the optimal. In this paper, a two-degree-of-freedom (2DOF) PID controller with a set-valued filter is designed, and double optimal control effect for servo tracking performance and interference suppression performance is realized by combining with the fuzzy self-tuning rules. The result shows that the scheme has the advantages of short adjustment time, small overshoot and strong anti-interference performance.

ABSTRACT. Magnetically controlled saturated reactors (MCSRs) operate through changing the degree of saturation of the magnetic valves by applying different DC excitations. In the practical working conditions, the two magnetic valves of the MCSRs are alternately saturated rather than simultaneously saturated. However, the vibration and stress of MCSRs considering the state of the magnetic valves alternately saturated had not been studied. In order to design an appropriate damping system or vibration isolation system for MCSRs, this paper studies the stress characteristic which is the inherent reason of vibration and noise. The magnetization and magnetostrictive curves of the silicon steel are tested in this paper. Based on the measured constitutive effect, an electromagnetic-mechanical coupled model for MCSRs is established based on the finite element method. Considering the electromagnetic force and magnetostriction effect of silicon steel, the magnetic field and stress are calculated for the MCSRs. The magnetic field distribution and stress distribution of the MCSRs under different working conditions is obtained from the calculation, which provides the theoretical basis for vibration and noise reduction of MCSRs.

ABSTRACT. The finite-control-set model predictive direct torque control (FCS-MPDTC) is a novel and promising control scheme for permanent magnet synchronous motors (PMSMs). An important feature of FCS-MPDTC is that the eight possible voltage space vectors or switching combinations of the power converters are directly taken into account as the control input of the system. Due to the considerable torque and flux ripples, to improve the performance of FCS-MPDTC, this paper presents an extended set of twenty modulated voltage space vectors with fixed duty ratio. To mitigate the computational burden caused by increased number of voltage space vectors, a pre-selective scheme is designed for the proposed FCS-MPDTC to filter out the impractical voltage vectors instead of evaluating all twenty voltage space vectors. The drive system efficiency of conventional direct torque control (DTC), conventional FCS-MPDTC and proposed method are investigated.

ABSTRACT. In this paper, voltage vector selection for the direct torque control (DTC) for surface permanent magnet synchronous motor (SPMSM) based on predictive control is proposed. Firstly, based on increasing or decreasing effects of the applying voltage vector on the amplitude of stator flux and torque of SPMSM, the proper voltage vector selection area of the DTC for SPMSM is given. Then predictive control is used to determine the angle of applying voltage vector in voltage vector selection area. A cost function of stator flux and torque’s errors is proposed to evaluate the performance of different angle of applying voltage vector whose amplitude is constant. The angle which results in the minimum cost function among different angles is selected as the angle of the applying voltage vector. As the applying voltage vector is selected from proper voltage vector selection area, it can always satisfy the control of stator flux and torque. Finally, space vector modulation (SVM) is used to generate the applying voltage vector. Simulation results show the DTC for SPMSM works properly under the proposed control strategy. Compared with conventional switching table, the proposed strategy can suppress torque ripple and reduce cost function and mean squared error of torque and stator flux. And due to the use of SVM, switching frequency is kept constant.

ABSTRACT. The topology of neutral-point clamped (NPC) is widely used for multilevel inverters, and the balance of the neutral-point voltage is one of the key technologies which determines the performance of Permanent Magnet Synchronous Motor(PMSM). Repetitive control can ensure control precisions by keeping the appropriateness of the control signal when the system is stable. In this paper, neutral-point balancing control scheme and repetitive control scheme used in the algorithm of PMSM drive system based on three-level topology was established to improved the dynamic and static performance of system. Our results indicates that the repetitive+PI control scheme provides better transient and steady state performance than classical PI control scheme for PMSM.

ABSTRACT. This paper proposes a model predictive torquevector control (MPTVC) scheme for four-switch three-phase inverter (FSTPI)-fed permanent magnet synchronous motor (PMSM). A cost function consist of a new constructed reference torque-vector is designed. Thus, the control of the FSTPI-fed motor drive with the capacitor voltages dc offset suppression can be ensured by only tracking the reference torque-vector. Simulation studies are conducted to verify the effectiveness of the proposed MPTVC method.

ABSTRACT. This paper presents a new slip compensation method for the traditional scalar control (V/f) of induction motors. Based on the level of q-axis component of stator current, the steady-state slip of motor speed is estimated by means of flux-oriented current tracking that is usually applied in vector control. The method features both the simplicity of scalar control and improvement on the performance of speed regulation. The simulation and experimental results are shown and discussed to verify the effectiveness of the proposed method.

ABSTRACT. As a response to the rare earth crisis arising in recent years, two new permanent magnet synchronous reluctance (PMSynR) motors with non–rare-earth materials are proposed for electric vehicle (EV) applications in this paper. The key feature of the motor is to adopt different magnet and flux-barrier combinations to obtain relatively high torque density, high power density and high efficiency. To verify the validity of the proposed motors, the electromagnetic performances are compared by using finite-element (FE) method.

ABSTRACT. This paper proposes a model reduction approach (MRA) for model predictive control of brushless doubly fed twin stator induction generators (BDFTSIGs). The complete power model is firstly divided into various small divisions with different coefficients. These divisions are then classified into three levels of subspaces through a local sensitivity analysis. A simplified model can finally be obtained by a further analysis of global sensitivity. The effectiveness of the proposed MRA and the accuracy of the simplified model are validated by the excellent control performance.

ABSTRACT. Since air-gap magnetic fields of brushless doubly-fed machine (BDFM) are produced by two stator windings of different pole pairs, the spatial harmonic contents of the BDFM are higher than conventional induction machines and have a considerable effect on the machine performance. To reduce the contents of main slot harmonics, the harmonic components of air-gap magnetic field for the BDFM are analyzed and a method of using the tooth notching in the stator and the rotor is introduced in this paper. A two-dimensional finite element method (2-D FEM) is applied to model a 72-slot stator, 84-slot rotor and 2/4 pole pairs prototype BDFM. The simulation results show that the method of the tooth notching reduces the first-order slot harmonic of air-gap flux density and torque ripple of the BDFM effectively.

ABSTRACT. This paper examines several techniques for determining the parameters of the Brushless Doubly Fed Reluctance Machine (BDFRM). Even though the mathematical model for this machine is like that of an induction machine, the very high leakages inductances prevent the use of the normal locked rotor and unloaded rotor tests. The accuracy of the parameters found is validated by machine testing and comparison with the FEA machine design.

ABSTRACT. This paper sets out to provide a rotor-centric view of BDFM operation, which shows the basis of its rotating flux pattern, aligning it with the known Natural Speed, and clarifying the synchronous and induction modes of operation of the BDFM. Based on rotor-centric view of the BDFM it is shown that the conventional design methods for the BDFM stator back iron can be modified, leading to a lighter and smaller machine. The proposed design concepts are supported by analytical methods and their practicality is verified using 2-D Finite Element (FE) modeling and analysis of three experimental BDFMs.

ABSTRACT. The novel three-phase rotary transformer is an attractive solution to replace the brushes and slip rings of doubly fed induction generators. The interaction of magnetic field produced by primary windings and rotating secondary ones makes it difficult to establish the dynamic mathematical model of the transformer. This paper presents finite element analyses of the novel three-phase rotary transformer and investigates its dynamic characteristics. The influence on the most important design parameters such as air gap length and phase voltages are discussed in detail.

ABSTRACT. The brushless doubly fed machine (BDFM) is an alternative to the doubly fed induction generator, widely used in wind turbines, without use of brush gears and slip rings. Rotor design is important for designing an optimal multi-MW BDFM. To date, nested-loop rotors have been extensively used in various BDFMs, however they may not be suitable for larger machines. In this paper, design optimization of a bar-cage rotor for the BDFM based on equivalent circuit analysis is presented and its performance verified with experimental results and compared to the conventional nested-loop rotor. A new BDFM with frame size D180 was built with two rotors, one has a nested-loop structure and the other has a bar-cage design. The performance of the BDFM with the two rotors is studied and experimental results will be presented in the full paper.

ABSTRACT. A novel brushless hybrid-excitation axial flux machine (BHAFM) is investigated in this paper. It is designed for electric vehicle which requires the ability of wide speed range and high starting torque of machine. Adopting the special structure of claw poles, BHAFM realizes the function of hybrid-excitation without brush and slip ring. Meanwhile, contrasted with traditional permanent magnet synchronous motor (PMSM), it has the merits of less demagnetization to permanent magnet (PM) and more flexible design. The comparison research mainly focus on the ability in the condition of flux weaken control, and the working principle of traditional PMSM and BHAFM in that condition is introduced.

ABSTRACT. Abstract—Brushless doubly-fed generator (BDFG) has a good application prospect on the wind power generation field. In order to improve the power density, a new type of dual-stator brushless doubly-fed generator (BDFG) with magnetic-barrier rotor is presented in this paper. The overall structure design method and mechanical performance of DSBDFG is put forward and analyzed. In addition, rotor bracket plays an important role for supporting inside and outside cage-barrier rotor, so the mechanical strength of the rotor bracket is calculated by using finite element method (FEM). Furthermore, the structure model and the influence of stator structure parameter on resonance phenomena are investigated for the structure optimization.

ABSTRACT. This paper presents a novel axial doubly salient electro-magnetic machine with a new double stator structure based on the traditional permanent magnet brushless DC motor and the switched reluctance motor. And according to the electromagnetic characteristics in different conditions by three-dimensional finite element method, a new control strategy is put forward. Simulation and experiment have verified the correctness of the analysis. The results indicate that the machine in this control strategy can run stably. It has high starting torque, small torque ripple, good speed expansion capability and favorable field-control performance.

ABSTRACT. In this paper, we propose a design model using numerical optimization technique and control technique aiming at improvement of efficiency of the low voltage BLDC motor because the utilization of low voltage motor is increasing for safety and convenience of electric motor use in recent industrial trends. The optimization technique is employed the generalized sensitivity technique and sampling minimization technique. In order to minimize current consumption, the switching method of the driving device is optimized using RSM with DE.

ABSTRACT. This paper proposes a modeling method of electromechanical actuator (EMA) system including nonlinear links and multi-body dynamics problems with flexible bodies. Since the two nonlinear characteristics can affect the dynamic characteristics of the system, the analysis of their effects on the system can be carried out closer to the actual situation. According to various situations, the mathematical model of the system is studied. Then the simulation model is established in Matlab software to verify the influence of nonlinear factors on dynamic characteristics of the system.

ABSTRACT. This paper presents a novel harmonic current injection method to optimize air-gap flux density distribution for multiphase induction machine (IM). The control objective is to generate a nearly rectangular air-gap flux for the best iron utilization. The proposed method uses air-gap flux orientation control (AFOC) and rotor flux orientation control (RFOC) to realize the real-time adjustment of the third harmonic current under various loads. The robustness and effectiveness of the proposed scheme has been validated by computer simulations and experiments.

ABSTRACT. This paper proposes a simple duty cycle modulated direct torque control (DDTC) for permanent magnet synchronous motors (PMSMs). DDTC sequentially output an active vector and a zero vector during each control period. The duty cycle of active vector is obtained using a duty cycle generator according to the torque error, which can avoid the complex calculation process associated with conventional DDTC. Simulation and experimental results are presented to validate the effectiveness of proposed DDTC. Furthermore, the comparative evaluation of proposed DDTC and conventional DDTC is conducted to verify the superiority of proposed DDTC.

ABSTRACT. In the applications like aerospace, it is important to drive the motor in high precision and high efficiency. The traditional switching inverter drivers output pulse mode voltage which brings lots of harmonics and influences the stability of motor drives. A multilevel-switching-linear hybrid (MSLH) scheme is proposed for the permanent magnet synchronous motor (PMSM) drives. It combines the advantages of multilevel switching inverters and power linear amplifiers: the high efficiency and the excellent linear waveform. The topology of MSLH scheme is proposed and the simulation is carried out to verify the performance of this system.

ABSTRACT. In this paper, the behavior of doubly-fed induction generator (DFIG) under unbalanced grid voltage conditions is analyzed and a control strategy based on complex-vector-resonant regulator is proposed. Compared with the traditional PI regulator, the positive and negative sequence currents can be regulated without sequential-decomposition process and this control structure has strong robustness parameter variations. Simulation and experimental studies validate the effectiveness of the proposed control strategy and the ride-through capability of DFIG under unbalance grid voltage conditions can be enhanced.

ABSTRACT. The maintenance cost of 8200 series electric locomotive operating in Korea is rising due to aging and lack of original technology. 8200 series electric locomotive operating have two auxiliary power systems. The auxiliary power system supplies power to the passenger cars. So It was related to the safety and reliability. There are many parts of auxiliary power system. Among that, The PWM modules are very important in 8200 series electric locomotive. This is because the PWM module is a power conversion device that is essential for powering the passenger cars. Also the price of PWM modules are very high. So maintenance cost of PWM modules have increasing. In this paper, Life Cycle Cost analysis was conducted for PWM modules of the auxiliary power system in 8200 series electric locomotive. In order to life cycle cost analysis, cost of breakdown maintenance and operating was applied.

ABSTRACT. Recently, the development of a system using the latest technology has been continuously carried out in order to solve the increase in the maintenance cost and the aging of the railway vehicle. Especially, in the case of 8200 series electric locomotives, which transport passengers and cargoes in Korea, the maintenance cost of railway vehicles has been increasing, and the latest technology is applied to make the products compatible with existing vehicles. Among them, the APS(Auxiliary Power System) supplies electric power to the carriage. This system requires power conversion devices and communication devices. The auxiliary power system performs communication via SIBCOS. In order to perform communication, the protocol defined in the standard must be applied, and when the system is normal, the master device does not generate an error signal. In this study, the fault code of SIBCOS in 8200 series locomotive auxiliary power system was analyzed for the development of the product considering the compatibility with existing. In addition, the failure code that was frequently displayed when applied to real vehicles was analyzed.

ABSTRACT. In-wheel motor system is recognized as the ideal drive system for electric vehicles. To reduce mechanical shock and electromagnetic impulsion brought by rigid connection between hubs and motor, our group proposed a novel permanent bistable electromagnetic clutch which can flexible connecting the motor and hubs. In this paper, several power supply schemes for the clutch are proposed and compared, then, pulsed power supply as a better scheme is further studied and optimal designed. Subsequently, the capacitance, charging voltage, coil turns and coil diameter are determined. Finally, experiments verified the power supply system we proposed.

ABSTRACT. This paper presents a 12-sector control method, based on the new zero voltage vectors (ZVVs), in direct torque control (DTC) of brushless DC motor (BLDCM). Compared to the 6-sector control strategy, this method has a better performance in reducing the torque ripple because it can effectively prevent the phase windings in commutation from commutated current freewheeling. The proposed method is validated by the experimental results.

ABSTRACT. This paper is about improving efficiency of an inductive coupling wireless power transfer (WPT) according to the distance between a transmitting coil and a receiving coil. When the distance between the transmitting coil and receiving coil is very short, it is called by over coupling and efficiency is low and output power is small. Sufficient power and high efficiency can be obtained with LLC resonance and the LC resonance operations according to clearance of two coils. The features are analyzed in two operations in detail. Experimental results are also shown to verify features and operation with a 5W prototype.

ABSTRACT. In this paper, an improved control strategy based on the duty ratio modulation, using the new zero voltage vectors (ZVVs) is proposed in direct torque control (DTC) of brushless DC motor (BLDCM). The conventional voltage switching table is modified according to this strategy to minimize the torque ripple. The strategy has been proved to be easy to realize, fast in dynamic response and insensitive to system parameters. The numerical simulation and experimental results show that the strategy is quite effective in reducing the torque ripple.

ABSTRACT. A compact behavioral model for SiC power MOSFET is proposed. By applying more degrees of freedom in the channel current expression, removing the drift resistance and rectifying junction capacitance mathematical model, the proposed model can accurately reproduces those static and dynamic characteristics in datasheet. The convergence problem of original model is solved and less simulation time is needed. Moreover, the model was promoted to simulate 1200V/300A power module, which is suitable for rail transportation application.

ABSTRACT. This paper presents a new framework for risk consideration of participants in electricity markets. Current approaches add risk measures to stochastic problem formulation in order to control the variation of the profits (costs). However, in the proposed method, the cumulative distribution function of profit is utilized and it is shaped based on the preferred risk levels of the producer (buyer). The features of this new method are compared with the current approaches based on a detailed case study performed on the problem of a producer participating in a three settlement market.

ABSTRACT. As shrinking the overseas nuclear power plant construction market, the number of producers and suppliers has been increased abandoning nuclear quality assurance programs because of decreasing the demand for safety grade items. It is difficult to supply equipment for installation and replacement of safety class electrical equipment of Nuclear Power Plants (NPPs) in Korea. Commercial Grade Items (CGIs) are inevitable to use as a substitute for safety-related equipment parts through Commercial Grade Item Dedication (CGID). In this work, we have performed to analyze regulatory laws, regulation and technical standards for quality assurance of CGI, critical characteristics and acceptance methods are necessary to clarify for safety and regulatory quality.

ABSTRACT. This paper presents a method to shed off the least important loads in a microgrid operated at constant frequency under the contingency of inadequate power generation. Different from conventional frequency deviation based load shedding, this paper discusses in detail how to shed off load based on the voltage deviation. The key issue is to differentiate whether the voltage deviation is due to sudden change of loads and renewable generation or due to insufficient power generation. By setting proper time margin, an error-free judgement could be made to shed off the least important loads.

ABSTRACT. In this study, we collected actual power demand data for small and medium sized industrial customers(SMEs) with high power consumption. Based on these collected data, a small microgrid system including a photovoltaic system and a battery system is constructed at a factory in a customer to improve power consumption efficiency. This system also includes a peak demand power controller to reduce the peak power, and a method for reducing the maximum demand power and the amount of power consumption is proposed in this study.

ABSTRACT. In this paper a novel method is presented to optimize distributed generation (DG) in distribution networks. The suggested method shows how DGs should change in their sizes and places, if it is necessary, to improve the voltage profile and total power loss of distribution networks. For this purpose, game theory is applied to model the optimization problem. At the first step, an appropriate game based on the Nash equilibrium is suggested. Using the specific features of game theory, the procedure of decision making in the operator centers of distribution grids is considered. Then, the optimization problem is solved by finding Nash equilibrium point. To solve the Nash equilibrium a specific kind of genetic algorithm (GA) called Nash GA is applied.

ABSTRACT. A fractional-order analysis model of chaotic oscillation in a 4D power system including synchronous generator exciter is presented in this paper. The dynamics of the system are investigated extensively by using this model. Firstly, the minimum order for chaotic oscillation occurring is calculated under the invariant system parameter set, then the influence on the dynamics of the system under variation of parameters is studied through bifurcation diagram and maximum Lyapunov exponent. The dynamic behaviors of the coexistence of attractors with different initial conditions are also investigated through the analysis of the trajectories and the Poincaré sections of the coexisting attractors. Finally, based on the stability theory and the feedback theory for the fractional-order nonlinear system, a controller is designed to realize the synchronization of two power systems.

ABSTRACT. Abstract — In order to study the method of fault tolerant control for axial field flux-switching fault tolerant machine under single-phase faults, a new control strategy has been proposed which combines the SVPWM tolerance algorithm and excitation of field winding, based on an inverter with fault tolerant topology called three-phase four-leg with field winding H-bridge. The theory of SVPWM tolerance algorithm has been analyzed in detail when the machine’s single-phase faults happen in this paper. Because of the particularity of AFFSFTM, the field winding can be used to assist fault-tolerant control, which is verified by simulation. Moreover, the experiments were done . AFFSFTM still can maintain normal operation after single-phase faults by using the proposed control method.

ABSTRACT. Three types of flux-regulation methods, namely storage capacitor discharge pulse (SCDP), constant current source pulse (CCSP) and quantitative flux-regulation pulse (QFRP) methods are analyzed and quantitatively compared. The simulation results show that the QFRP possess good performance in regulating the magnitude, direction, duration as well as the parameter insensitivity. In the same magnetization and demagnetization process, the experimental results confirm that the QFRP enables the stator permanent magnet memory machine (SPMMM) to achieve larger back EMF and less harmonic component.

ABSTRACT. A novel 6/13-pole axial field flux-switching permanent magnet (AFFSPM) machine has the advantages of compact structure, large torque density, high efficiency and good fault tolerance. In order to reduce the influence of load mutation and the variation of system parameter on the control system of AFFSPM machine, and to improve the stability of drive system, the control method of AFFSPM machine is researched. In this paper, the sliding mode control method based on SVPWM is applied to the drive system of the AFFSPM machine. The simulation model of the drive system under the control strategy is established by MATLAB/Simulink. The waveforms of three-phase currents, speed and torque are researched and analyzed. The simulation results show that the drive system of the novel AFFSPM machine has good static and dynamic performances under the control of the sliding mode control strategy.

ABSTRACT. This paper presents the theoretical analysis of field-weakening performance of a permanent magnet (PM) memory machine. A modified circle diagram is proposed to graphically illustrate the maximum torque field-weakening control strategy for memory machine drives. It is shown that a maximum torque capacity can be obtained by the proper control of the armature current and magnet flux. The influence of machine parameters on the performance of PM memory machine is also investigated. The results can be used to design a PM memory machine for a given flux-weakening performance.

ABSTRACT. Abstract--Axial field flux-switching permanent magnet (AFFSPM) motor is a novel stator-type brushless permanent magent motor. It has these advatanges including short axial size, large torque density and good fault-tolerant capability. In this paper, the structure of a novel U-shaped stator core AFFSPM motor and operation principles are analyzed in detail, based on which the mathematical model of the motor is derived. And then the drive system of the AFFSPM motor, in which the vector control and direct torque control methods are respectively applied, are simulated and researched by MATLAB/Simulink software. The static and dynamic characterisitics are compared and analyzed under the conditon of the two control methods. Although the dynamic response of direct torque control is quicker than that of vector control, the former has better static performances and low speed characteristics. Finally, the relative experiments are done to validate the performances of the AFFSPM motor under the vector control.

ABSTRACT. A dual-rotor axial field flux-switching permanent magnet (DRAFFSPM) machine is proposed and investigated in this paper. The static characteristics, such as the field distribution, the PM flux-linkage, the back-EMF, the winding inductance, the cogging torque, and the output torque, etc., are investigated based on the 3D finite element (FE) method. In order to gain sinusoidal back-EMF and reduce the cogging torque, the structure of the DRAFFSPM machine is optimized. The theoretical analysis is validated experimentally. It shows that the phase back-EMF is sinusoidal, and the machine can be used as a permanent magnet brushless AC motor.

ABSTRACT. Parameter optimization of active suspension equipped in in-wheel motor driven electric vehicle by the use of genetic algorithm is presented in this paper. Installing the motors in the wheel can result in an increase in the unsprung mass, which greatly deteriorates the suspension ride comfort performance and road holding ability. The structure which suspended shaftless direct-drive motors has the potential of improving the road holding capability and ride performance. The genetic algorithm is employed to obtain the optimal parameters under different road profiles. Parameters of the motor suspension (damping and stiffness coefficients), vehicle suspension and active controller are optimized based on quarter vehicle model. This optimization tries to minimize the vertical acceleration of sprung mass and motor, dynamic force transmitted to the motor as well as suspension working space and road holding capability. Simulation results of passive suspension, model with unoptimized and optimized suspension parameters are compared.

ABSTRACT. Electrical machines are gaining more and more attentions from the researchers now, especially for the electric vehicle application, where the high power density and high efficiency are needed. Compared with radial flux machine, axial flux machine can have higher torque density and efficiency due to its tight structure. However, most of the axial flux machines are designed with the surface mounted permanent magnets (PMs) rotor, where the reluctance torque ability is eliminated. To improve the torque ability of the axial flux machine, a new axial flux interior permanent magnet machine (AFIPM) is proposed and analyzed in this paper. The rotor of the proposed AFIPM is manufactured by the rolling the electrical steels as a ring core, then the PMs are inserted in the holes of the rotor ring, the axial side of the rotor ring is designed with the several different steps to eliminate the harmonics of the back EMF as well. The static performance and electromagnetic parameters of the AFIPM is calculated and it shows that the reluctance torque ability of this AFIPM is very good, based on the 3D finite element method (FEM) and frozen magnetic permeability technology

ABSTRACT. An analytical model is established to predict the air gap magnetic field distribution of surface mounted permanent magnet machine (SMPMM) with isodiametric magnetic pole based on the two-dimensional field theory in polar coordinates. The governing equations and the associated boundary conditions are formulated and solved. Both the magnetic field distributions, when the stator is slotted and slot-less, are calculated by the proposed analytical method and are compared with the finite element analysis results.

ABSTRACT. This paper adopted an improved off-line identification method that can accurately estimate the stator resistance and stator inductances and the magnetic flux linkage of SPMSM. In the single-phase locked-rotor test and DC test, a single-phase sinusoidal AC(alternating current) signal and DC(direct-current) signal was injected to the motor after filtering the input signal to obtain the real and imaginary part of the voltage and current signals, then the motor resistance and inductance can be calculated. In the no-load test, a three-phase sinusoidal AC signal was injected to the motor, then the flux of permanent magnet motor can be deduced by the motor steady-state model and power equivalence principle.

ABSTRACT. The global supply of rare earth magnets becomes risky with the rapid increasing demand of rare earth permanent magnet (PM) machines. This paper focuses on the PM Alternating Current (AC) machines with magnet direct-reuse concept, aiming to mild hybrid vehicle applications. The designs shall fulfill all the constraints and functionalities of the applications. Meanwhile, the designs shall follow the principle of simple magnet disassembly. Several SPM topologies are chosen to study thence. In addition, the feasibility of implementing recycled magnets on SPMs is investigated.

ABSTRACT. This paper introduces nonlinear modeling of a new dual rotor machine named dual-rotor permanent magnet reluctance (DRPMR) machine. The paper proposes the varying magnetic network model of DRPMR machine considering possible saturation and nonlinearity according to its novel structure. The final results are verified by the finite element method (FEM) and results prove the validity of the proposed model.

ABSTRACT. This paper proposes a novel 16/10 segmented rotor switched reluctance machine (SSRM) for belt-driven starter generators (BSGs) of hybrid electric vehicles. The stator of proposed SSRM consists of two types of stator poles: exciting pole and auxiliary pole, and the rotor of proposed SSRM is made up of a series of discrete segments. Firstly, the concept of the conventional SRM and proposed machine is presented. Secondly, the design rules of proposed SSRM are described. Finally, the finite element method (FEM) is employed to get the static characteristics of the proposed SSRM, including the magnetic flux distribution, magnetic flux density, inductance characteristic, torque characteristic and continuous torque. Result shows that the torque ripple of proposed SSRM is low.

ABSTRACT. As the permanent magnet synchronous motor (PMSM) system is the key part of power system in EVs, the efficiency of PMSM system has great influence on the energy consumption of EVs. To increase the endurance mileage of EVs in one charge, it is important to improve the system efficiency of PMSM drive system. This paper proposes a novel analytical nonlinear loss model for PMSM system which can calculate fundamental motor loss, harmonic motor loss and inverter loss together. The PMSM fundamental loss can be calculated by the analytical model which can predict copper loss and iron loss together. The nonlinear switch characteristics and conduction characteristics of power devices can be fitted by the nonlinear model, by which the accurate inverter loss is acquired in a fast and simple way. this paper applied double Fourier integral analysis to calculate the harmonic current caused by the PWM output voltage of inverter in the analytic method, and creates a whole-frequency harmonic loss model of PMSM. Based on the novel nonlinear loss model of PMSM system, this paper proposes an efficiency optimization control strategy which can significantly increase the system efficiency without serious effect on the system stability in the whole operation condition of PMSM system for EVs. Both analytical and experimental results prove that efficiency optimization control can decrease the system loss and improve the system efficiency of PMSM system.

ABSTRACT. Recently, electric vehicle is paying attention because of its eco-friendly characteristics. Interior permanent magnet synchronous motor(IPMSM) is the most popular type of electric motor because of its compactness and high efficiency. But recently, rising costs of permanent magnet and demagnetization issues which result from high current density make interests in induction motor for vehicle traction field. In this paper, design method of induction motor for maintaining torque performances at field weakening region is proposed. Analysis results are verified by 2D Finite Element Analysis(FEA).

ABSTRACT. This paper presents a field-circuit coupled design and analysis method for the permanent magnet synchronous motor (PMSM) system used in electric vehicles. The time-stepping finite-element method is used to simulate the motor system, which integrates the electromagnetic field analysis of the motor prototype and the control algorithm of the drive system. A two-dimensional transient electromagnetic field model is built for a 15-kW PMSM in ANSYS Maxwell, and a double closed-loop vector control circuit model is set up in ANSYS Simplorer. The coupled simulation system is then obtained by integrating the two models. Transient simulation is conducted through field-circuit coupled analysis. The simulation results and the experimental results show a good consistency. The research of this paper provides a powerful tool for the PMSM system design.

ABSTRACT. This paper presents a technique to reduce electromagnetic torque ripple of an IPMSG with fractional-slot, concentrated-winding which is connected to a rectifier and a boost converter. Firstly, the generator was controlled using DC current control of the boost converter. The generator torque ripple with this conventional method was found as 29.7% of rated torque which is significant to cause generator losses and drive train vibrations. Hence, a new control approach to reduce the ripple was proposed. The proposed strategy directly controls the electromagnetic torque of the generator using a rotor position based torque estimator. The new method was able to reduce torque ripple to 7.6% of the rated torque. The generator was controlled at rated speed and rated current with each of methods mentioned above for the analysis. The improvement was experimentally verified using a 4kW prototype fractional-slot, concentrated-wound IPMSG.

ABSTRACT. The paper proposes a moving average filter (MAF) model predictive control (MPC) based on grid virtual flux estimation electric vehicles (EVs). An MAF, which acts as an ideal low pass filter (LPF), can eliminate the effect of unbalanced grid voltage and unknown characteristic harmonics. Both the two cascaded LPF and the proposed MAF-based MPC strategies can achieve bi-directional power flow for G2V and V2G operations. Compared with the two cascaded LPF based MPC, the proposed control method can improve the system performance by reducing the active power overshoot and the current total harmonic distortion (THD).

ABSTRACT. The direct matrix converter has been regarded as a promising AC/AC conversion topology and it is being researched. Motor drives are one of the main potential applications of the matrix converter. This paper carries forward the application of matrix converters in AC motor drives using direct torque control (DTC). In the common DTC scheme for the matrix converter, two vectors with the maximum amplitudes are used to control the torque and flux. In the proposed approach, the input voltage vector sectors are redefined, therefore a modified and simplified switching look-up table is obtained. In this case the most appropriate vector to be applied is uniquely determined and the number of switch actions are reduced. The excellent dynamic performance is obtained by selecting the maximum vector. Flux and speed are controlled effectively. Simulation work is carried out for an induction motor and results verify the effectiveness of the proposed DTC control in matrix converter based AC drive systems.

ABSTRACT. This paper proposes a novel integrated control system including PMSM drive and vehicle-to-grid (V2G) technology based on open winding PMSM. It realizes bidirectional energy flow for Electric Vehicles in V2G control mode and motor drive mode. These modes can be switched easily and smoothly according to commands from integrated controller. Compared with the traditional control system in V2G mode, the proposed control system uses motor stator winding as filtering inductor, eliminating the additional filtering inductor and decreasing the volume of the Electric Vehicles control system and the cost of the product. It also increases the power density of electric vehicle control system. At last, the correctness and feasibility of the proposed integrated control system are verified by theoretical analysis and simulation.

ABSTRACT. In recent years, researches and developments of next generation power semiconductor devices using wide-band gap semiconductors such as SiC and GaN become actively. Switching speed of these devices are more than ten times faster than conventional silicon IGBTs. Therefore, EMI emissions generated by power converters will be further widened in near future. Especially, since an influence by radiated EMI becomes serious, it is urgent to realize effective radiated noise reduction techniques. The authors proposed an active common-mode filter (ACF) capable of reducing radiated noise from power cables which are connected to power converters, and evaluated its reduction effect of radiated noise by using an oscillator as a common-mode (CM) noise source . In this paper, the ACF is applied to a motor drive system fed by a PWM inverter, and an attenuation characteristic of CM voltage is evaluated.

ABSTRACT. The radiated acoustic noise from a traction motor at low speeds is dominated by the noise of electromagnetic origin. For a motor operated from pulse width modulated (PWM) converters, the switching frequency of the converter will have a large impact on the noise. The total harmonic distortion of the motor phase currents and thus also the exciting forces, will decrease with increasing switching frequency. Furthermore, changing the switching frequency will shift the frequencies of the exciting forces, hence have an influence on the coincidence with structural resonances of the motor. Tests have been performed on a traction motor and a decrease in sound pressure level with increasing switching frequency has been quantified and analyzed.

ABSTRACT. This paper presents a multifunctional interface circuit for the battery-ultracapactior hybrid energy storage system (HESS). The circuit can realize both the voltage equalizing of the battery banks and energy exchanging between two kinds of the energy source, thus maintaining the reliable work and the health of the battery bank and keeping the ultracapacitor (UC) in a good state of charge (SOC). The simulation results show the effectiveness of the proposed multifunctional interface circuit for the HESS.

ABSTRACT. The battery direct current resistance (DCR) characteristic and power capability depend significantly on the temperature. It is essential to investigate systematically the temperature dependence of battery DCR for achieving desirable power capability prediction. Based on a large amount of battery test data, this paper proposes a model to describe the temperature dependence of DCR. This model has been applied for battery power capability prediction, and the results are verified by experimental results.

ABSTRACT. Over the past few years Hybrid Electric and Electric propulsion systems have found significant attention as the most plausible substitute to fossil fuel based engines. Hybrid Electric Vehicles (HEV) have been around for more than a decade and extensive research has been taken out to make these vehicles more efficient. With advances in technology, manufacturers such as Tesla and Chevrolet have successfully launched a number of Electric Vehicles (EV) in the past 5 years. In despite of all this success, HEVs and EVs currently face challenges in energy storage systems (ESS) with regard to a variety of parameters and to overcome these issues research has been done on different types of ESS systems to extend the range of such vehicles. Flywheel Energy Storage Systems (FESS) have regained interest in the last decade and the application of kinetic energy recovery system (KERS) in the Formula 1 has reinforced the case of using FESS in HEV and EV. In this study, the integration of an FESS system within a hybrid electric propulsion and an electric propulsion system is considered and with the help of Bond-Graphs as a multidisciplinary modelling tool the impact of this integration is analyzed and compared with each other.

ABSTRACT. Abstract—Energy crisis and environmental pollution are a serious threat to human survival and sustainable development. To alleviate the energy crisis and maintain the living environment of mankind, people develop and utilize new energy sources such as solar energy and wind energy. In order to ensure the safe and reliable use of the battery, and improve the performance of the battery after group, the battery management system has become the key technology of the wind energy storage battery system and the electric vehicle power battery system. Battery balance management is the core technology of battery management system and the focus of the current research. Combined with this background, this paper focuses on battery equalizer and equilibrium strategy. The research strategy is to transfer the equilibrium energy directly from the high voltage single cell in the battery pack to the ground voltage cell.

ABSTRACT. In order to achieve effective utilization of an electric storage device composed of batteries, we constructed a charge and discharge system. We verify the system operation by their own simulation analysis and actual measurement.

ABSTRACT. The existence of filters, series RLC and parallel RLC excite resonance in multi-parallel grid-connected inverters systems. This paper proposed dual closed-loop with active damping control strategy to suppress resonance. The external current loop was controlled by PR (proportional-resonant) regulator and provided feedback on grid current. On the same time, the internal voltage loop with active damping restrained the filter resonance effectively. Simulations in MATLAB/Simulink circumstance were constructed to confirm the feasibility of the proposed method. The simulation results show that it owns ability to suppress resonance resulted from inverter itself, parallel resonance and series resonance, also, strong robustness while changing parameters.

ABSTRACT. Abstract —In this paper, a new approach for suppressing force ripples is proposed, which is based on active disturbance rejection control and harmonic spectrum analysis of dent force. It is possible to take advantage of dent force characteristic and uncertain disturbances estimation to achieve better control performance. The effectiveness of proposed method is verified by simulated results.

ABSTRACT. This paper compares the performance of surface PM generators when operated with a switched-mode rectifier and an inverter. An analytical model including losses for the surface PM generator and power electronics controller is developed and validated against simulations and experimental results. This is used to generate efficiency maps as a function of output power and speed for the generator operating with four control methods: rectifier, unity and non-unity power-factor controlled switched-mode rectifiers, and an inverter. The efficiency maps and the required control parameters to achieve maximum efficiency are presented and discussed.

ABSTRACT. This paper proposes a method to estimate the stator winding temperature of permanent magnet synchronous motor (PMSM) driven by direct torque control (DTC). The DC components are generated in the stator currents to calculate the stator resistance by injecting the torque into the DTC system of the PMSM, and then the stator winding temperature is estimated by the relationship between stator resistance and the stator winding temperature. The simulation results validate the effectiveness of the proposed method.

ABSTRACT. This paper presents a robustness-improving discrete-time current controller utilizing predictive current control (PCC) for permanent magnet linear synchronous motor (PMLSM). The stability and robustness of the PCC system is highly affected by the parameters mismatch between the controller and the plant, and the inherent digital control delay can limit the bandwidth. Toward this, an integrated method considering both the parameters variation utilizing an adaptive internal model estimation with improved variable-gain adaptive law and the time delay compensation in discrete form is proposed. Validity and effectiveness of the proposed method is demonstrated by the simulation and experimental results.

ABSTRACT. This paper presents a control strategy for squirrel cage induction generator(SCIG) based on commercial vehicle using engine-generator system. For this, the conventional slip- and vector control method using PSIM is used to illustrate the characteristics of the system. The simulation results of the control methods are presented and discussed.

ABSTRACT. This paper concerns performance of a direct torque and flux controlled 14-pole/18-slot fractional-slot concentrated-winding interior permanent magnet synchronous machine (FSCW-IPMSM) in deep flux-weakening region. For the optimum operation of the machine, voltage limit, current limit, MTPA and MTPV trajectories defined on the torque-flux plane are incorporated in the control algorithm. In the experiment, it was found that the conventional flux-weakening algorithm of DTFC is inadequate for the studied FSCW-IPMSM to deliver a satisfactory performance at high speeds. Therefore, a modified voltage control strategy was included in the algorithm to achieve the wide speed range of the machine. Experimental results verify the effectiveness of the proposed method. A very wide speed range of 9:1 was achieved for the studied FSCW-IPMSM under the proposed method.

ABSTRACT. Advanced machine control techniques, such as MPC and DB-DTFC, relies heavily on accurate machine parameters and inaccurate parameters can degrade control performance. Since machine parameters vary due to multiple factors, it is necessary to embed real-time parameter identification method into these control techniques. This paper is dedicated to exploring parameter identification method integrated on DB-DTFC. Making use of a flux observer combining the current and voltage model, a MRAS based parameter estimator is constructed to obtain magnetizing inductance and rotor time constant of the machine. Experimental results show torque control accuracy can be improved through our method.

ABSTRACT. Active magnetic bearings (AMBs) provide a new proper solution for the high-performing rotating equipment. The active controlled electromagnetic forces of AMBs levitate the rotor without any contact with the stator. The advanced controller design is one of the key issues associated with AMBs. This paper deals with the application of μ synthesis to the control of AMBs. The parametric uncertainty of the AMB model is detailed to be represented by the constraint of real system so as to reduce the conservatism. Weighting and penalty functions are introduced based on the objectives of AMB performance. Finally several simulation and experiment results show the effectiveness of this proposed control methodology.

ABSTRACT. In this paper, an emergency power supply system for building DC distribution using emergency generator is suggested. The proposed emergency power supply system uses an emergency generator for power supply in AC distribution. Since most emergency generators for building currently output 3-phase AC, the AC/DC power conversion stage is essential for DC power distribution. For this reason, in this paper, a 2-level AC/DC converter for 13.3kW emergency generator is designed to propose an emergency power supply system suitable for building DC distribution. System analysis through the simulation result also verifies the possibility of the proposed system

ABSTRACT. Optocouplers comprising an optical sensor and electrical readout circuits are commonly fabricated on a single chip to reduce the size of electrical systems and enlarge circuit board capacity. Nonetheless, the inclusion of two separate components on a single chip still results in high cost and area overhead exceeding those of monolithic chips. In this paper, we propose an optocoupler integrating an optical sensor and readout circuit on a single chip using the TSMC high voltage bipolar-CMOS-DMOS (BCD) process. The combination of high current bipolar junction transistors with this mature CMOS processing technology makes such a monolithic chip achievable and the reduced chip size greatly expands its applicability. This approach to circuit integration also helps to enhance the reliability of the resulting chip, while reducing the overall costs and facilitating mass production.

ABSTRACT. Temperature rise is one of the main factors that affect the safe operation of electric vehicle. In order to improve the heat efficiency of the motor, the water-cooled motor of circular circumferential waterway for mini electric vehicle was studied as an object in this research, the structural parameters of the channel are optimized and analyzed from the following aspects: the width of the adjacent channel, the width and the height of the channel. A numerical model for coupling the fluid field and temperature field of a motor with different waterway parameters is established, comparing and analyzing the temperature rise distribution of different cooling structure parameters, the optimum cooling system parameters are obtained, which provides a reference for the design of the cooling system of the small and medium sized water cooling motor.

ABSTRACT. The extensive applications of switched reluctance motor (SRM) have been limited due to its drawback of torque ripple. Thus, the reduction of torque ripple is an important problem in studying the SRM. A novel 16/10 segmented SRM (SSRM) is proposed in this paper. The proposed SSRM performs well in terms of torque ripple and tolerant-fault characteristic. The stator of the proposed structure is constructed from exciting and auxiliary stator poles, while the rotor consists of a series of discrete segments. Moreover, the torque ripple is evaluated by comparing with the conventional 8/6 SRM. Finally, the tolerant-fault characteristic of the proposed SSRM and conventional SRM are compared as well. The finite element method (FEM) is employed to demonstrate the prominent advantages of static and dynamic characteristics of the proposed SSRM.

ABSTRACT. In this paper, comparisons between two permanent-magnet-free (PM-free) machines, namely a wound-field flux-switching machine (WFFSM) and a switched reluctance machine (SRM), covering skewed-rotor and straight-rotor structures are conducted. The topologies and operation principles of the WFFSM are illustrated firstly. Then, the effects of rotor skewing angle on static characteristics, e.g., open-circuit phase flux-linkage and back electro-motive-force due to field currents, electromagnetic torque, and torque ripple, have been investigated in depth by finite element analysis (FEA). Consequently, the optimal rotor skewing angle is determined. In addition, comparisons between the WFFSM and a prototype SRM having the same stator outer diameter and stack length are conducted, and the results indicate that for both PM-free machines, the skewed-rotor WFFSM exhibits better performance, including larger torque capacity and smaller torque ripple. Moreover, the reductions of average torque and torque ripple due to rotor skewing for the WFFSM are acceptable, whereas for the SRM rotor skewing results in degraded performance.

ABSTRACT. A novel axial-flux switched reluctance machine (SRM) which has segmented stator and rotor is proposed. The copper loss and iron loss are effectively reduced due to the very short flux path formed by the special structure. The design process with a modified method is presented, and the geometric dimensions are obtained. The electromagnetic characteristics of the machine are analyzed by 3D finite element method (FEM), and the performances under both motoring and generating conditions are evaluated as well.

ABSTRACT. Different from permanent magnet synchronous machine, switched reluctance motor(SRM) is featured as high local flux density, high current variation ratio in the winding of medium, high power and high speed. Therefore, the hot spots in the winding will be caused by eddy current effect. When current flows through winding, skin effect is generated by the high frequency alternating current due to the high switching frequency. Furthermore, proximity effect especially located at slot tip is caused by the flux, which generates significant current displacement and amounts copper loss. Therefore, in this paper, theeddy current analytical model of winding in SRM is investigated, where arbitrary current waveform originated from control strategy is considered. Furthermore, finite element method is employed to analyze for 3-phase 50kW SRM and compared with analytical model. Finally, effect of winding parameter and layout on copper loss is presented for guiding motor design.

ABSTRACT. This paper presents a comparative performance analysis of segmental type switched reluctance motor (SRM) for heating, ventilation, and air conditioning (HVAC) applications. Electric motors are the basic components of HVAC system, which control the airflow and therefore cannot be separated from it. Hence, a motor with high efficiency, high electric utilization, and variable speed drives is necessary. Unlike conventional SRM, segmental type utilizes short flux path, which improves electric utilization and decreases core loss in the stator and rotor that may lead to higher efficiency. Motor variables are selected to meet the requirements of HVAC system. The characteristics of the described motor are compared through flux, torque, direction, and efficiency. Finite Element Analysis (FEA) analysis is used to analyze the static and dynamic performance of the motors.

ABSTRACT. Switched reluctance Motor (SRM) has gained wide acceptance as a variable speed drive, mainly due to its simple construction, robustness, fault tolerated operation, high starting torque, and high-speed operation. However, it suffers from torque ripple and imposed noise. The control of SR motor is achieved via controlling switching-on angle, switching-off angle, and current profile independently. Complex control topologies are found in the literature to satisfy loading conditions at different speeds. Previously, the authors have proposed the correlative angle switching technique for SRM. The technique robustly defines the relation between current profile and switching angles. In this paper, the performance of a complete control system is validated using extensive simulated study for traction application that follows the desired motion pattern. Results show the effectiveness of correlative angle switching technique and how it can be implemented for traction application accompanied with current control.

ABSTRACT. Switched reluctance motor (SRM) is suitable for high-speed driving and enables high output. However, reduction in efficiency due to an increase in iron loss caused by an increase in speed is a problem. In this paper, by adjusting the firing angle and varying the current waveform and loss, it was verified that the firing angle realizing the highest efficiency exists. Moreover, it was confirmed that firing angle at the maximum efficiency shifted when changing the rotation speed. Furthermore, by separating the loss into copper loss and iron loss, we confirmed how they change depending on firing angle.

ABSTRACT. In this paper, two combined star-delta winding configurations are compared when employed to Synchronous Reluctance Motors (SynRMs). In addition, their influence on SynRM performance is investigated in the normal operation. The analysis is carried out using the transient Finite Element Method (FEM) and experimentally validated using a 5.5 kW prototype SynRM.

ABSTRACT. In this paper, a new reluctance synchronous machine (RSM) is proposed. The key of proposed RSM is simple and asymmetric rotor with salient pole structure. The rotor is similar to the rotor of switch reluctance motor, offering highly mechanical robustness. Meanwhile, the salient pole structure is designed to be asymmetric, which is used to reduce torque ripple further. Moreover, the different shifting angle of salient pole is presented to reduce different harmonic order of torque ripple. The theoretical analysis is verified by the finite element method.

ABSTRACT. CMLFSPM is especially suitable for urban rail transit application due to their high power density and simple structure. In this paper, a direct thrust control method for a complementary and modular linear flux-switching permanent magnet (CMLFSPM) motor is proposed. The Direct Thrust Control (DTC) method has the merits of faster torque response and impregnability of motor parameters. The performance of the proposed control method is demonstrated by simulation results with MATLAB/Simulink software.

ABSTRACT. This paper proposes a new double-stator flux-switching permanent magnet (DS-FSPM) motor where the stator-partitioned structure and two air gaps are adopted. By using finite element method, the proposed motor is comprehensively evaluated for the electromagnetic performances of torque capabilities, torque ripple, demagnetization, PM usage efficiency, flux-weakening capability in detail. Moreover, a conventional single-stator flux-switching permanent magnet machine with the same overall dimension and the same PM usage is also analyzed and fairly compared. The simulation results indicate that the DS-FSPM motor can not only retain higher torque density, but also exhibit better flux-weakening ability and enhanced demagnetization withstand capability.

ABSTRACT. Hybrid excited axial field flux-switching permanent magnet (AFFSPM) (HEAFFSPM) machine is a novel stator-excitation hybrid excited flux-switching machine, which combines the advantages of the AFFSPM machine and hybrid excited synchronous machine. In this paper, the structure feature of the HEAFFSPM machine is analyzed, and the mathematical model is established. In order to improve the power factor of drive system for the HEAFFSPM machine and make full use of the inverter capability, a kind of unity power factor (UPF) control method is proposed, and the operating performance of the HEAFFSPM machine is investigated. The simulation and experimental results indicate the unity power factor can be achieved at different speed and load while the constant torque region is extended by using the UPF control method compared with the zero d-axis current control method.

ABSTRACT. In order to make the flux-switching permanent magnet machine (FSPM) have favorable control characteristics, this paper researched a field-oriented vector control system. The id=0 vector control strategy was applied to FSPM and the high frequency signal injection method was adopted to identity the initial rotor position of FSPM. The running and regulating characteristics of the machine were all analyzed by experiments. The analytical results of this paper show that the vector controller has good applicability in hardware structure and algorithm, which will greatly promote the industrialization of FSPM.

ABSTRACT. In this paper, a new double-sided linear flux-switching permanent magnet (DLFSPM) motor for electromagnetic launch system is proposed, in which the mover only consists of yokeless iron while the permanent magnets and armature windings are all located on the stator. Hence, this motor incorporates the merits of high thrust density of permanent magnet linear motor and high relability of linear induction motor in high speed electromagnetic launch system. The mathematical model and field-oriented control strategy of DLFSPM is investigated. The simulation results indicate that the DLFSPM can offer a very good dynamic performance based on the selected control strategy.

ABSTRACT. Flux-switching permanent magnet machines(FSPMM) have doubly-salient structure and permanent magnets on the stator. So, it is possible to increase the rotor speed and prevent from irreversible demagnetization of magnets. In this paper, we analyze the distribution of iron losses in the FSPMM using a two-dimensional finite-element method (2D FEM). As a result, we can get the information for high efficiency FSPMM design.

ABSTRACT. Flux Switching Machines (FSMs) are a relatively modern technology that provides several advantages in specialized applications. FSMs offer high torque density and a robust rotor design which has attracted interest. This paper will provide a review of the current state-of-the art developments in FSMs technology on several aspects such as design topologies, their practical applications, ease of fabrication, efficiency, power density and cost based on recent research efforts.

ABSTRACT. Abstract — In this paper, a variable structure magnetic network model of bearingless flux-switching motor (BFSM) is constructed considering the rotor eccentricity. Based on the network model analysis method, the maximum value of the rotor to stator tooth width ratio and the peak of winding flux linkage is deduced; the electromagnetic torque is derived based on the peak of flux linkage, and the mathematical model of levitation force is further deduced by magnetic network. Finally, the fast design of key variables is verified to be effective by comparing with the finite element analysis and the experimental results.

ABSTRACT. This paper investigates methods of magnet mass reduction in linear flux switching permanent magnet(LFSPM) machines by introducing tapered consequent poles. Based on the finite element analysis (FEA) three different models are designed, investigated and compared.The obtained results indicate that by adopting the proposed tapered ferromagnetic poles a considerable saving of material cost and weight is obtained without sacrificing the machine performance.

ABSTRACT. Direct-drive robotics is quite attractive because of its high efficiency, high robustness and wide application prospect. This paper is to propose a new double-stator hybrid flux switching permanent magnet (DSH-FSPM) machine for the direct-drive robotic applications. The key is to integrate the distinct merits of high torque density, flux-modulation, high fault-tolerant capacity, and low torque ripple together. First, the machine design and flux switching principle are analyzed to illuminate the basic operation principle. Also, the machine performance shows that the inner and outer torque ripples offset with each other and contribute to the low torque ripple less than 7%. Furthermore, with the addition of the DC current, the machine flux and EMF can be weakened, which can enlarge the flexibility and stability for the machine operation. The performances of the machine verify the feasibility of the new topology for the direct-drive robotics.

ABSTRACT. Aluminum material with different distance away from transceiver coils on source side and load side is studied in this paper. The introduction of aluminum shielding incurs eddy current effect, which weakens the self-inductance of transceiver coils. Simulation and experiments are carried out to find optimal shielding position to realize efficient and fast charging.

ABSTRACT. Due to the advantage of power transmission over certain distance without using wires, the wireless power transfer system has attracted more and more attention. This paper proposes an analytic approach to investigate the transfer efficiency of magnetically-coupled inductive wireless power transfer system with constant power load. The mathematical model of the wireless power transfer system with constant power load is developed, and the resonance condition is derived. Furthermore, the closed-form transfer power and transfer efficiency of the system are proposed. The influence of output power, output voltage, input voltage, resonant frequency, and mutual inductance on the transfer power and transfer efficiency are analyzed. This paper can provide a guideline for engineers to follow in the application of magnetically-coupled inductive wireless power transfer system with constant power load.

ABSTRACT. Abstract— This paper presents a comparison between the properties of solenoid coil and planar spiral coil designed for wireless power transfer (WPT) system. The impedance properties of two structural magnetic coils are discussed. And the influence of the structural parameters (such as diameter, turn number, number of layers, etc.) on the transfer performance of magnetic resonance coupling WPT system are also analyzed. Furthermore, the magnetic resonance coupling WPT experimentsbased on the solenoid coil and planar spiral coil are carried out and compared. Finally, for these two kinds of coils, the recommendations on the suitable applications have been put forward. I. INTRODUCTION The magnetic coils are most critical part of the wireless power transfer (WPT) system, which play a role in energy coupling and transmission[1]. As the dimension and structure of magnetic coils will have an impact on the performance of WPT system, there are numerous studies on the properties of solenoid coil and planar spiral coil[2-4]. For example, as for the solenoid coil, many researchers have done a lot of research in the relationship between transmission efficiency, size of coil and distance[4]. For the planar spiral coil, the features, design and optimization of the structure has also been discussed[5]. However, in this paper, the comparison of the solenoid coil and planar spiral coil in the WPT system is focused on. In this paper, through the theory and simulation analysis,the characteristics of these two types of coilsare summarized. And themagnetic resonance coupling WPT experimentsbased on the solenoid coil and the planar spiral coilarecarried out and compared.Furthermore, the advantages and disadvantages of these two kinds of coils in the magneticresonance coupling WPT are discussed. Finally, the suggestions for the suitable applications of two types of coils have been made. II. THECOMPARATIVEANALYSIS The shapes of these two types of coils are shown in Figure 1. For the traditional spiral coils, the WPT system can obtain a better transmission performance due to its good directional properties. The reason is that the magnetic field excited by solenoid coil is uniformly distributed.

a. solenoid coil b. planar spiral coil Fig.1 The two types of coils As for the planar spiral coils, the relevant WPT system can achieve an excellent frequency selectivity. Besides, for the system composed of planar spiral coils, its optimal load resistor value for impedance matching can be smaller. In addition, the impedance properties of two structural coils have both analyzed. Owing to space constraints, the impedance curve for the traditional spiral coil is shown as Figure 2.

Fig.2 The curve of impedance value, reactance and impedance angle III. DISCUSSION Based on the theoretical analysis and experimental verification, the magnetic resonance couplingWPT system composed of the solenoid coil is more suitable for long-distance wirelesspower transfer, which means somewhere with plenty of room. For another, the plane spiral coil is very thin,more suitable for application to some small electrical appliances, which is conducive to the magneticresonance coupling WPT system tends to miniaturization.In addition, the more results will be depicted in the final version. IV. REFERENCES [1] Giulia Di Capua, Nicola Femia, Giovanni Petrone,et al.Power and efficiency analysis ofhigh-frequency Wireless Power TransferSystems. Electrical Power and Energy Systems. 84, pp.124-134, 2017. [2] Kim, Jinwook, et al.Optimal design of a wireless power transfer system with multiple self-resonators for an LED TV.IEEE Transactions on Consumer Electronics.Vol.58No.3, pp.775-780, 2012. [3] Chen C JC, hu T H, Lin C L, et al.A study of loosely coupled coils for wireless power transfer[J]. IEEE Transactions on Circuits and Systems II: Express Briefs,57 (7): 536-540. [4] Hugo Marques, Beatriz V Borges. Contactless batterycharger with high relative separation distance andimproved efficiency [A]. IEEE InternationalTelecommunications Energy Conference ( INTELEC )[C].2011. 1-8. [5] Tan Linlin, Huang Xuelang, Huang Hui, et al. Transfer efficiency optimal control of magnetic resonance coupled system of wireless power transfer based on frequency control[J]. Science China, 2011,41(7):913-919. [6] TeckChuanBeh,TakehiroImura, Masaki Kato,Yoichi Hori. Basic study of improving efficiency of wireless power transfer via magnetic resonance coupling based on impedance matching [C].Industrial electronics ISIE,2010 IEEE International symposium on Bari.2010,July:2011-2016.

ABSTRACT. Electric model based in the duality between the electric and magnetic circuit taking into account the misalignment characteristic of transformer of a WPT is proposed. Being a model based in the constructive characteristic of the transformer the model represent better the misalignment effect and the simulation values are more precise in comparison with the T model that is widely used.

ABSTRACT. Contactless transformer is a key part of the inductive contactless power transfer (ICPT) system. In this paper, a high coupling coefficient contactless transformer is proposed with asymmetric trapezoidal shape cores. With 3D finite element methods(FEM), this paper calculates coupling coefficients of the transformer at different inner lateral side distances and bending angles of the magnetic cores and obtains the distribution of magnetic field and the power transmission characteristics. The results show that the high coupling coefficient contactless transformer can improve the coupling performance and power transmission efficiency of the ICPT system.

ABSTRACT. Contactless transformer is the key component in inductive power transfer (IPT) system and its coupling coefficient (k) will directly affect the power transfer efficiency. This paper studies a contactless transformer applied in movable vehicle with the structure that primary and secondary side are asymmetrical. By analyzing the magnetic flux distributions of the transformer, magnetic reluctance circuit of this contactless transformer is proposed. Further optimization based on the reluctance circuit was taken, and the finite element methods (FEM) calculation results confirmed the theory analysis.

ABSTRACT. This paper analyzes the relationship between the load and the efficiency of contactless transformer with multi-pickups which are in series or parallel connection. An optimal load resistance can be got with parameters of contactless transformer at which the efficiency is the highest. Connection mode of multi-pickups affects the optimal load resistance, which is larger at series or smaller at parallel. A prototype was constructed and test was carried out to extract the parameters of transformer. Theoretical statements are supported by the experimental results.

ABSTRACT. This paper describe the RBF neural network fault diagnosis methods, then combined the actual gas regulator case is studied. The results show that fault recognition rate can reach 62.5%. In order to further enhance the recognition rate of fault diagnosis, the introduction of the principal component analysis (PCA), combining PCA and RBF neural network technology, based on PCA and RBF neural network is put forward in the gas regulator improved method of fault diagnosis, for gas regulator provides a new method of fault diagnosis. Through inputing the actual sampling data into the algorithm, simulation show that PCA-RBF neural network fault recognition rate than RBF neural network fault recognition rate increased by 25%, thus PCA-RBF Neural Network is effectiveness method.

ABSTRACT. The paper presents a method of the series arc fault for DC systems. The aim of the study is to find some current characteristics, which can be significant for the purpose of arc detection. The validity of the proposed method is testified by analyzing the arc fault current signal. The low voltage series DC arc study is carried out on the currents waveforms acquired during some tests on electric appliances. The pattern matching algorithm is then used to detect and classify the arc fault. As a result, the method is effective in detecting and classifying the arc fault, and easy to be realized in the practical cases.

ABSTRACT. This paper deals with the method of a fault detection and diagnostic system for the domain control units, a vehicle equipped with advanced vehicle E/E systems. The fault detection is a technique for improving the diagnostic coverage of vehicle E/E systems by introducing harsh environments to fault injection in hardware paths and error handling code in software paths. This results in fault detection of time-varying nature and magnitude. This thesis develops a set of methods able to detection these fault issues in a systematic manner with functional safety systems.

ABSTRACT. This paper presents a new image processing technique based method to measure the locus of spinning spindle vibration. Spindle vibration detection is always a difficult problem in textile industry. Compared with the conventional method which utilizes vibration sensor and is just applied to measure the vibration of the spindle without load, the proposed method can be applied to the spindle with load. A camera with high-speed shutter is enrolled to take pictures of the spindle top surface. According to a serials of the obtained images, several methods are used to locate the center of the spindle surface, based on which the locus of spindle vibration with these centers is given. Furthermore, the proposed method can also be used to measure the locus of other similar high-speed rotating components.

ABSTRACT. Although a number of 800kV UHVDC (Ultra High Voltage Direct Current) transmission lines has been built, there is lack of general UHVDC electroscope equipment and relevant standards. Therefore, a non-contact electroscope based on MEMS (Micro-Electro-Mechanical System) is proposed in this paper. The reasonable measuring position of the electroscope is selected. The distribution of electric field of UHVDC transmission lines in different operating modes, such as double-pole operation and single pole operation, are obtained through simulation and analysis. The alarm threshold of electroscope is set and the field test is carried out. The effectiveness of the electroscope is verified.

ABSTRACT. Development of a Wireless Telemetry-Based Traffic Sensor Technology to Overcome the Lead Cable Breakage in AVC

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ABSTRACT. Positive and negative discharge mechanisms in atmospheric air have been numerically analyzed using a fully coupled finite element analysis. Until now, many research works have examined discharge analyses, but the discharge mechanism has not yet been explained in detail numerically. In a positive discharge, the electric field intensity at the streamer head can be enhanced owing to the superposition of a Laplacian field and a field from the positive space charge density. With this increased electric field intensity and attraction force between the negative electrode and positive space charge density, the positive streamer can move straight from the positive tip electrode to the negative plane electrode. In a negative discharge, the polarity of the electrode is reversed, and the positive space charge covers the negative electrode. Excess negative ions move toward the positive electrode, and a Trichel pulse is formed in the discharge current. To analyze this space charge propagation, we employed charge continuity equations for carriers such as electrons and positive and negative ions. These equations include ionization, attachment, and recombination effects, and Poisson’s equation for electric fields. A secondary emission effect is included as a boundary condition on the cathode surface. Tip-plane electrodes were implemented in 2D axial symmetric model with a gap radius of 1 mm. To verify our numerical setup, the numerical results were compared with experimental data found in the previous literature.

ABSTRACT. This paper focuses on parameter estimation for linear oscillatory actuator (LOA) utilized in linear compressor. A recursive least square (RLS) based method has been developed to estimate the resistance, inductance and thrust coefficient of the motor. Considering the time-varying effect of the system, a forgetting factor is introduced to improve the dynamic tracking precision. A mover displacement estimator is presented to verify the accuracy of the proposed estimated parameters. Simulation and experimental results are shown to demonstrate the effectiveness of the proposed method.

ABSTRACT. Self-sensing actuation is defined by the ability to derive the state of an actuator by exclusively measuring physical signals produced by the actuator itself, which can be done thanks to the reversibility of the piezoelectric effect. Most modern piezoelectric self-sensing methods have made use of charge measurement with several kinds of piezoelectric actuators (e.g. linear stacks, cantilevers, shear stacks, etc.). This paper provides a generalized model and approach for describing the system equations of piezoelectric actuators regardless of their morphology with actuator parameters being calculated separately. This will provide an understanding of each of these parameters’ influence on the self-sensing performance. A test setup verifying the authenticity of the model is being assembled.