ABSTRACT. In this paper, a new model for calculating current and voltage distribution on the shield conductors of power substations during ligthning strikes reaching the physical installations is presented. The model is based on multiconductor transmission line theory. First, the electrical parameters of vertical and horizontal shield conductors are calculated, then modal analysis is used to obtain a two port network representation for all the shield conductors, considering both their direction and inter-conection. The model is solved using a simplified representation for the subattion grounding grid. Finally, the model results are compared with those presented by other authors in the literature, with good results.

ABSTRACT. This paper presents a comparative study of the use of grain oriented electrical steels (GOESs) and non–grain oriented electrical steels (NGOESs) in magnetic shunts of power transformers. GOESs and NGOESs are analyzed and compared in magnetic shunts of a real 190 MVA three–phase three–legged power transformer using 3–D finite element (FE) simulations. Simulations are carried out to analyze the magnetic/thermal impact of the GOES shunts and NGOES shunts in the power transformer. The shunts are modeled utilizing their magnetization properties and the structural elements of transformer are modeled utilizing surface impedance boundary conditions (SIBCs). Furthermore, commercial GOESs and NGOESs are utilized in the shunts and their stray loss and temperature impact is analyzed. Finally, a cost analysis is carried out to compare the material and manufacturing costs of GOES and NGOES shunts. Results show that NGOES shunts are as effective as convectional GOES shunts in reducing the stray losses, temperature, and costs in power transformers without putting in risk their operation.

ABSTRACT. In this paper, system identification methods are used the modeling of nonlinear systems within a small scale process plant, focusing the analysis on state-space descriptions. The experiments for the adjustment of parameters are discussed, taking in account the limitations of the plant. The experimental results reveal that the identification model schemes suggested are adequate and demonstrate its accuracy and efficiency.

ABSTRACT. Ferroresonance is a phenomenon that occurs in voltage in the form of aperiodic oscillations that cause transient overvoltages, mainly in transformers. This phenomenon must be considered in the design of electrical systems, since it presents high levels of distorted voltages in a system. In the present article simulations are shown in ATPDraw, presenting serial type ferroresonances through different scenarios, observing the behavior of voltage signals. For the presence of ferroresonance, certain capacitive values are considered in cables and power supply voltage levels of the system, in addition, the impact on the location of switches is analyzed, observing how ferroresonance behaves under different operating conditions.

ABSTRACT. This work proposes a wideband planar microstrip antenna for 3G, LTE and Wi-Fi Bands, describing the simulation, design implementation and measurement. Actually the minaturization of microstrip antennas is an important challenge of radio engineering. The objective is reduce dimensions, weight and cost, in order to meet the miniaturization requirements of portable communication equipment and be installed inside of it. This kind of antenna is sufficiently small to be used on radio mobile devices, which satisfies gain, resonance frequency, impedance and low cost. It covers 1.7 – 2.4 GHz frequency band, which it is assigned to particularly wireless mobile communication services.

ABSTRACT. This paper presents the design and the online implementation of a monitoring station for a distillation column. The purpose of the monitoring station is to supervise and ensure the quality of the distilled product, through the analysis of the process operation, which can reduce production costs. The monitoring station is designed for a distillation column pilot plant in a batch-type operation mode, it is based on temperature measurements. It has 7 Pt-100 RTD temperature sensors, located in the boiler, the condenser and in 5 plates of the column body.

ABSTRACT. In this paper, the performance of a QKD system emulated by means of experimental C&DH and Communications subsystems of a CubeSat using a novel proposed technique based on the homologation of propagation models using COTS devices for the classical channel is presented. This technique does not require the spacecraft to be in its final orbit and it is based on the experimental performance of the aforementioned subsystems using the two-ray propagation model. The principal advantage of the technique used is the calculus of the Final Secret Key Rate (FSecKR) considering a different testing condition, i.e., without launching the CubeSat into the final orbits nor using an aircraft as launching emulator. The final results show that the FSecKR can be emulated for the free space propagation model considering the overall performance in the two-ray propagation model.

ABSTRACT. A model based Fault Diagnosis algorithm for a class of nonlinear systems is proposed and applied to the DC/DC buck converter-inverter-DC motor system. With the proposed algorithm faults in the sensor that measures the current flowing through the inductor of the buck converter, mechanical faults in the rotor and motor bearings that affect the viscous friction and faults in the transistor that regulates the output voltage of the buck converter are detected and isolated; these faults are modeled as sensor, system and actuator respectively. Faults in sensor and actuator are modeled as additive and the mechanical faults as multiplicative.

ABSTRACT. Solar photovoltaic power forecasting is a key issue for grid operators, power generators, as well as for other entities. This work presents a global solar irradiance estimation scheme using image features. Features are based on grayscale image, as well as red, green and blue layers of the color images. Several features has been analyzed and compared, and those with higher correlation with solar irradiance has been used for the prediction process. The compact image acquisition system was build with commercial and not expensive hardware, and open-source software. Two types of lenses have are compared: normal (flat) and fisheye lenses. Results show that fisheye lenses offer a better performance that normal

ABSTRACT. Lithium-ion-based Battery Energy Storage System (BESS) play an important role in solving power supply problems in micro-grids due to their performance characteristics such as high power, high efficiency, low self-discharge, and long lifespan. Therefore, is essential to know the BESS useful life, especially by understanding how its degradation process evolves over time. In this context, this article presents a methodology capable of analyzing the degradation process of the BESS Li-ion batteries when used into a micro-grid. Since BESS degradation is a consequence of how the battery cells are operated (e.g.; initial and final state-of-charge (SOC) values within each cycle), we propose the use of a technique capable of estimating an equivalent degradation factor regardless of their operation. To assess BESS degradation, an economic dispatch is carried out, which incorporates the use of a BESS inside a micro-grid. The economic dispatch is formulated as a MILP optimization problem that allows the BESS to supply the electricity demand during an eight-hour period of energy autonomy per day. Results show a useful life of 2233 cycles of usage of the BESS. Thus, if the BESS works under the proposed conditions, its lifespan will be over 7-years approximately. In this case, it is demonstrated that the BESS operates under high SOC ranges, (100-0%), (90-0%) and (80-0%), inferring that in each cycle almost all the available stored energy is consumed.

ABSTRACT. This work presents the design and development of a remote monitoring system for the blades’ strain in a small wind turbine (SWT). The monitoring system allows real-time transmission of the stress to a remote client which processes the information in order to suggest further control actions to guarantee a reliable wind turbine operation. Experimental results show an increased axial strain of the blade when the rotational speed of the wind turbine is increased. Additionally, an efficient transmission of the stress measurements is achieved by two communication approaches (wired and wireless) to a remote station, which logs and processes the information.

ABSTRACT. In this study, the analytical Jensen wake model is described and implemented to estimate the velocity deficit in the wind park domain. Velocity deficit distribution is discussed for a given wind park layout for different wind directions. In this model, the wake-wake interaction is modeled by the superposition principle. The total electric power produced by this wind farm is then obtained by using a power curve obtained from an eolo-electric generator dynamical model. Simplicity of this model might allow its use in electric power forecasting tasks, layout optimization, and other power systems applications.

ABSTRACT. In this paper, we investigate the use of low cost wireless sensor networks for the development of an environmental monitoring system that can be used to visualize air pollutants in real time by means of a web application. Measuring nodes were implemented, using low cost analog and digital sensors, for collecting data about air pollutants such as CO2 and dust particles concentrations present in the environment. The system works in such a way that the values measured by the sensor nodes are encoded and sent via Wireless to the Gateway (Raspberry pi) by means of Xbee pro S1 modules. The data are decoded and stored in a local database. Afterwards, a web application makes a PHP connection with the database, and data are plotted in realtime, using the HighChart JavaScript library with AJAX methods and JSON notation. To check the functioning of the system and to compare the behavior of the sensors, measurements of the concentrations of CO2 and dust particles were taken outdoors and inside an underground parking lot.

ABSTRACT. This article presents the development of a breadth-first search algorithm to find the shortest collision-free path from an initial point to a final point using graph theory, and the design of a mobile robot with the capability to operate with IoT-based technologies. An example is presented implementing the calculated route in the designed robot operated remotely. The developed robot will serve as a workbench to test cooperative control schemes in which the exchange of information varies over time.

ABSTRACT. The emergence of new technologies and the opening of hardware and software platforms for the development of embedded systems, has facilitated the design, integration, and development of new communication monitoring and control systems. In recent years, the world population has grown rapidly, so the demand for fresh and healthy foods has increased its demand. Besides that, there is a widespread search for a more natural and healthy alimentation, that is why there is a tendency for people to start growing and harvesting their own food. The main objective of this paper is to design and develop the automation of a greenhouse for self-consumption using a free development platform, which accelerates the integration process, reducing time and execution costs.

ABSTRACT. In this article the proposal of an architecture of a middleware for an Internet of Things (IoT) system for urban farms is made, which is composed of three levels with a middleware level between the application layer and the link, validated in a real-time web system that uses protocols and application development standards on the cloud

ABSTRACT. Adaptive algorithms used for active noise control systems require a high convergence speed in order to be usable in real ANC applications. Affine projection (AP) algorithms offer a high convergence rate, however, this speed entails a high misadjustment. AP algorithms have been combined with other algorithms to address this misadjustment level, these combinations are known as a convex combination. However, such combinations tend to be computationally complex which precludes them from being used in ANC applications. This work presents a new convex combination, composed of the Filtered-x Error Coded Affine Projection and the Filtered-x Error Coded Least Mean Square Algorithm (CC FXECAP-FXECLMS), with the aim of obtaining an algorithm that retains the speed of the AP while achieving misadjustment levels of the LMS, while at the same time producing an algorithm with a computational complexity low enough to be practical for use in real ANC applications. Test results have confirmed the algorithm’s capabilities and proven that the algorithm is suitable for this role.

ABSTRACT. Induction Motors are very important machines for most industries, and an unexpected interruption of them may cause an emergency plant breakdown. There are different spectral analysis techniques that can be used in induction motor signals of voltage, current or vibration, to identify different motor failures, but all of them have limitations. Specifically, there is not a technique capable to detect the broken rotor bar (BRB) failure in all induction motors cases. The Nonlinear Mode Decomposition (NMD) is an adaptive tool based on time-frequency spectral analysis techniques, that identifies and decompose a signal in interdependent oscillations. The method is based on the Windowed Fourier Transform or the Wavelet Transform, in an adaptive form, and it can decompose a signal in different meaningful oscillations, for a reliable analysis. In this work, the NMD have been used, in a combination with the multiple signal classification (MUSIC) and a digital resampling, to detect the BRB fault, analyzing current induction motor signals. The methodology is tested with both simulated and real signals from induction motors with different levels of BRB failure, obtaining satisfying results.

ABSTRACT. An active vibration control approach for suppression of harmonic mechanical oscillations and, simultaneously, efficient tracking of angular position trajectories for induction motor is proposed. The introduced forced oscillation suppression scheme is based on virtual dynamic vibration absorbers. Numerical results are also presented to depict the capability of the original dynamic control approach for suppression of synchronous vibrations. A effective position trajectory tracking specified for an induction motor in presence of harmonic disturbing torque is shown as well.

ABSTRACT. In this paper, we investigate the use of Variational Mode Decomposition (VMD) for the analysis of seismic signals obtained from the Cotopaxi Volcano in Ecuador. The VMD method is proposed here as a method for noise attenuation to improve the event detection and the identification of the starting and end points of seismic events. The main advantage of the VMD over previous studied methods is its robustness for reducing noise and the number of features necessary to distinguish amongst the signals. Preliminary analysis shows that seismic events such as volcano-tectonic (VT) earthquakes and long-period (LP) events can be identified after applying the VMD to the seismic signal due to the fact that the modes obtained are considerably different between these types of seismic event, therefore this decomposition could also be used to extract features for an automatic classifier. Further observations show that the same process for obtaining the modes of the signal can also be applied to detect the presence of events using a fixed-size window and an amplitude threshold, the numerical results show a 99.26% accuracy for obtaining the events onset and ending points.

ABSTRACT. The signal compensation was performed for two temperature sensors, an infrared pyrometer and a K-type ther- mocouple, which are used to measure and control the tem- perature in an experimental dilatometer by Joule heating and controlled atmosphere. Sensor signals were corrected by com- pensation polynomials determined experimentally and encoded in LabVIEWTM. The compensation polynomials were validated with the experimental thermal history, correcting the tempera- ture signal of both sensors. Finally, compensation polynomials were implemented in the temperature control system of the experimental dilatometer to exchange the signal sensor from a low to high temperature range.

ABSTRACT. This paper deals with the implementation of an image compressor based in the LOCO algorithm, on a Zynq device, for use on board an nanosatellite provided with a camera. The implementation differences compare to the original work are described Results obtained an future work are discussed.

ABSTRACT. With the inclusion of network interfaces always connected to embedded systems, the concept of Internet of Things emerges. Today, IoT devices are in virtually all human activities facilitating the quality of life of people. Despite the advantages of these devices, there are also some drawbacks, one of the main ones being cyber security. One of the technologies currently in vogue to mitigate cyber security problems is blockchain. The overall blockchain approach is to be implemented on the server side, where computing capabilities are not as limited as in embedded systems. This paper proposes a methodology to assess the blockchain technologies. To evaluate the proposed methodology a comparative study of various blockchain technologies that can be implemented in embedded systems particularly for use in smart meters with SBC Raspberry Pi has been conducted. The results show that lightweight implementations of Blockchains are better for embedded systems.

ABSTRACT. This paper performs an experimental and numerical study to analyse the effect of micro-fins on the heat transfer coefficient of an aluminium alloy 6061 subjected to a constant heat flux in a heating system by effect Joule. For numerical simulation, two user-defined Functions (UDF) were implemented in a commercial program that solves the constitutive transport equations with the control volume method, the first UDF is used to establish the generation of Heat by electric current and the second UDF to calculate the coefficient of heat transfer by convection based on the dimensionless numbers of Grashof and Prandtl. The experimental results show that for a constant heat flux both sheets (with fins and without fins) reach different maximum temperatures; 400 º C for the specimen without micro-fins and 320 º C whit micro-fins. The heat transfer coefficient characteristic of the system is improved by 25% on average using micro-fins in aluminium sheet 6061.

ABSTRACT. The Kalman filter algorithm is applied to provide estimates of position and velocity from noisy position measurement data. Position data were obtained from a vision system designed to track the swimming path of a rat to measure spatial memory and recognition functions in a setup called the Morris water maze test. These tests are used with rats to study neurological functions. Although the computer system is reliable, the data can be disturbed, either by effects of changes in lighting, or mismatch in camera placement. In this work, it is shown that the Kalman algorithm has satisfactory performance in the elimination of large noise data values, and that it is very important to consider the measurement noise as a way to force the algorithm to underestimate such measurements, which contain remarkable errors. The results show the great ability of the algorithm to model the noise and reduce its effect. However, there is a compromise between noise reduction level and excessive data smoothing. Numerical values for distance, average velocity and total time for several tests are given. This approach can be applied to analyze stored data as well as to real-time data.

ABSTRACT. This article presents the analysis of the trajectory of a real hand index finger in order to design a mechanism that realizes this movement. We start with a graphical analysis using the Kinovea software identifying the real path curve measured in a person. Based on these data, we do the design of the finger articulated mechanism by using CAD software. To validate the obtained data, we use the geometric method implemented in a MATLAB script and simulation in the Adams View software. As a result, we obtain the percentage of similarity between curves that is 77% and between the endpoints of the trajectories that has a value of 99.9%. With these values and depending on the mechanism designed, the possible grips that will be implemented in a biomechatronic hand prosthesis are proposed.

ABSTRACT. Diabetic foot is one of the main complications experienced by diabetic patients. An early diagnosis and an appropriated treatment can prevent serious foot problems. This paper presents a criterion to identify thermal changes in the plantar temperature distribution. This criterion is based on the comparison of plantar temperature distribution with a reference distribution obtained from control subjects. A characteristic distribution in one and two dimensions are proposed. To measure the similarity degree, four similarity measures are used: Kullback-Leibler divergence, Jensen-Shannon divergence, Quadratic distance and Earth Movers distance. A 85.9% of 220 samples of diabetic patients presented a change in the plantar temperature distribution which can be a precursor of some complications.

ABSTRACT. Lung sounds represent a relevant source of information about the state of the lung parenchyma. Accordingly, several efforts have been made to obtain a quantitative characterization as well as a classification of respiratory information. This paper proposes a methodology for the characterization of multichannel lung sounds (LS), based on the feature extraction from the joint time-frequency domain through the short-time Fourier transform in order to contend with the non-stationary nature of LS. Subsequently the classification into two classes, the healthy and the sick, was performed by an artificial neural network. The average percentage of correct classification for new subjects was 79.68% for healthy subjects and 81.88% for patients diagnosed with diffuse interstitial pneumonia. Results indicate that the average percentage of correct classification for healthy subject improved when compared to results obtained in previous efforts of our research group where other techniques, such as univariate and multivariate techniques, that assumed stationarity of data were used.

ABSTRACT. Investigation of electrocardiogram (ECG) signals is of importance to the medical community because heart diseases are among the principal causes of death in the world. Measurement noise typically does not allow for an accurate extraction of the ECG signal features. Therefore, much attention has been paid in recent decades to design efficient algorithms. In this paper, we propose using the unbiased finite impulse response (UFIR) smoothing technique to extract signal features in state space. The UFIR-based algorithm designed is compared to methods based on the wavelet transform, morphological transform, and threshold-based detector. Higher accuracy of the estimator proposed is demonstrated in applications to signal denoising and features extraction employing real ECG data.

ABSTRACT. In the present work, the artificial intelligence is used, through neural networks, in the diagnosis of power transformers for the interpretation of the results obtained in the frequency response analysis test. The results of the classification of three types of failures in this technique are exposed. The characteristics of the statistical indicators that function as input variables of the neural network and the reason for implementing a multilayer network with backpropagation algorithm, in the training are exposed. The results of the discrimination of acceptable or not acceptable state of the transformer are presented and if it has any of the following faults: open winding, short circuit winding and winding with a point to ground. The response of the neural network is determined in case of study of real transformers.

ABSTRACT. The implementation of power electronics and new operational contexts in electrical systems for power generation demand the need to analyze, evaluate impacts and mitigate the events of faults caused by harmonics. For this reason, in this article we present the fundamental concepts of harmonics and some faults caused by harmonics through simulations, such as inrush currents, resonances and ferroresonances. The Matlab and ATPDraw programs were used for the simulations.

ABSTRACT. In this research work, the main models of distribution lines are detailed and compared. Standardized three phase, two phase and one phase configurations are used. It was concluded that for high values of soil resistivity ( p> 1000 Ω-m ) any model can be used, however for other values of resistivity the model to choose will depend on the required accuracy.

ABSTRACT. In this paper, a new analytical method for the analysis of Magnetic Levitation (MagLev) systems is proposed on the example of the so-called Thomson’s ring prototype. The method establishes the dependence of the primary and induced currents and also the equilibrium height of the levitating object on the input voltage through the mutual inductance of the system. The mutual inductance is calculated by employing the analytical formulae previously obtained. The resulting analytical solution of the dynamical model of the system can be effectively implemented in the control of the electromagnetic shock absorbers and suspension systems.

ABSTRACT. This paper presents a reduced order approach to the modelling of induction machines for the purposes of power transfer between asynchronous networks. The method of interconnection between the networks under consideration is a variable frequency transformer (VFT) whose technology is rooted in that of an induction machine. Attempts to apply a high-order model to VFT studies have been met with numerical instabilities and unacceptably long computation times. A reduced order approach therefore serves to reduce the complexity of the simulation by neglecting transient behaviour. The classical fifth order method is presented, upon which a third order and first order model are derived. These differ from the traditional reduced order models due to the inclusion of an otherwise neglected frequency differential term. Care has also been taken to avoid algebraic loops during simulation so that additional delays need not be introduced. The performance of the models is then analysed when they are operating as an induction machine and then as a VFT for asynchronous power transfer simulations. The result is a stable, low-order model that performs correctly under a wide range of VFT operative scenarios, including asynchronous and different-frequency networks connected to its terminals.

ABSTRACT. Wind power generation capacity has been increased following the targets set by many governments. Variability and uncertainty are inherent characteristics of wind power generation resulting in technical and economical challenges for power system operators. The unit commitment (UC) problem determines the power generated by each generator in order to minimize power system operating costs. In this paper, we propose a wind speed scenarios reduction using Self organizing Map (SOM) in order to solve the unit commitment problem using a reasonable number of wind speed scenarios that take into account the uncertainties related to the stochastic variable (wind speed). The results obtained show that the proposed methodology is able to characterize the uncertainty related to power injected from wind farms. Furthermore, the simulations results show that for the system under study, the scenarios reduction technique decrease the computational burden required to solve a SUC problem.

ABSTRACT. This paper reports on the design of a radio frequency rectifier for energy harvesting applications. The design method comprises the measurement of small-signal S-parameters of a Schottky diode at different DC levels and the use of a numerical approximation method to characterize a large-signal diode equivalent circuit. Using this model a RF rectifier is designed and fabricated to operate at 1.9 GHz. The designed rectifier consists on a single serial diode topology with radial stubs to filter the harmonics produced by the diode.

ABSTRACT. Single-phase cascade multilevel inverters (CMI) allow to feed loads with multiple voltage levels, which reduces the total harmonic distortion (THD) when compared with traditional three-level inverters. Reducing the THD makes the filter size smaller and cheaper which contributes to improve the overall performance of the power converter. These advantages make CMI attractive in several applications like: photovoltaic (PV) systems, active filtering, motor drives, among others. Transformerless grid-connected PV systems require a specific design of the pulse width modulation (PWM) strategy in order to deal with the common mode current (CMC) issue. Then, five levels CMI can be controlled by using different PWM strategies since the electrical circuit can be configured in multiple combinations. In this paper, a PWM sequence is proposed in order to deal with CMC issue in a CMI devoted to transformerless PV systems. Numerical and experimental results show the proper operation of the inverter and the reduction of the CMC

ABSTRACT. The objective of this paper is to design a prototype for a 4 degrees of freedom (DOF) robotic arm and validate its behaviour using Matlab and Solidworks, so that this manipulator is able to follow time-varying trajectories with its end effector through the implementation of PID control.

ABSTRACT. In this work the synchronization problem in the fractional-order unified chaotic system and its implementation via the equivalent electronic circuit is investigated. To overcome this problem, an approach to get the synchronization regime between two fractional-order unified chaotic systems based on a feedback controller is proposed. To apply the synchronization scheme an electronic circuit is designed and implemented using the development board Arduino Uno among with Matlab-Simulink and finally, some experimental realizations validate the proposed approach.

ABSTRACT. This paper proposes a buck converter with an LC input filter for power factor correction when connected to the grid by means of a non-controller rectifier. The output voltage is regulated to a constant reference by using a conventional controller over the voltage error. This converter may find potential applications, for instance, by supplying a constant voltage to LED based lighting systems and in energy storage applications. In this paper conditions for discontinuous conduction mode operation and theoretical current and voltage waveforms are provided. A voltage regulation controller is also presented along with experimental results which were performed on a low power experimental setup. The controller regulates the output voltage to a given constant reference and discontinuous conduction mode allows the input current envelope to follow the grid voltage waveform.

ABSTRACT. In this paper, a bank of nonlinear controllers is proposed for boost dc-dc converters in cascade connection (well-known as optimizers). Each optimizer is stabilized at its maximum power point by using a feedback linearization technique plus a conventional proportional and derivative controller. The proof of the internal stability is given by taking into account an electrical representation of the internal dynamics. The innovative nature of the proposed methodology features an improvement of the transient state of the system with a minimal steady state error even though conventional maximum power point tracking algorithm (MPPT) is used. Co-simulation tests (MATLAB and PSIM) are carried out by considering partial shading conditions in order to evaluate the performance of the controllers for the boost dc-dc converters in distributed maximum power point tracking (DMPPT) applications.

ABSTRACT. The paper presents the implementation methodology for Self-Timed modulators and their synchronous equivalent. An OQPSK (Offset Quadrature Phase Shift Keying) modulator is used for the ZigBee standard, and is modified with the addition of asynchronous control blocks with dual-rail structures for removing the clock signal. A comparison of synchronous and asynchronous modulators was performed and the implementation was carried out in two different FPGA technologies, where increased performance and reduced on power consumption was observed.

ABSTRACT. Power generation through renewable energies has had a very strong impact in recent years, since thousands of GW of clean energy are being generated annually around the world. Most of this energy is generated by solar photovoltaic modules which transform the solar radiation into electrical energy. The electrical energy that is generated by the photovoltaic modules can be injected to the grid through to the use of power electronic interfaces such as centralized inverter systems or dc-ac converters. This article focuses on the comparison of two versions of the three-phase dc-ac converters of the centralized type. The first topology consists of three single-phase inverters, and the second one consists of the three-phase bridge. This comparison consists on the evaluation of reactive power compensation task and the photovoltaic energy injection task, for both converter versions under balanced and unbalanced conditions.

ABSTRACT. This paper presents an architecture of teaching online laboratories based on services. The laboratory was designed to facilitate collaboration and customization to users. It gives them a common access point to laboratory resources that can be accessed anytime, anywhere, and which can be customized for user preferences, profile privileges and access limitations. This laboratory can be used in any teaching course. A case study of an online laboratory in a networking course is presented; in this, undergraduate students can remotely control instruments and devices. The effectiveness of our approach has been measured and evaluated through student satisfaction as part of cognitive load theory.

ABSTRACT. In this paper, we present an algorithm for the geometrical characterization of Diptera mosquitoes based on morphological characteristics and size relationships within their wings. The software has been written using NI LabVIEW and consists of two main stages. First, it manipulates the image to enhance the pattern detection. Second, it analyzes the detected patterns to obtain a set of eleven numeric parameters that describe the sample. The objective is to use this algorithm as the first step towards the development of an automatic classifier of Diptera Mosquitoes considering the relevance of this order for the human being.

ABSTRACT. The subject most frequently failed in the block of first semester subjects on various engineering degrees taught at the Technological Institute of Morelia, Mexico, is "Fundamentals of Programming", and this leads a high percentage of students to give up their studies. In this paper, we present a computer tool that students can use to practice what is learned in the classroom wherever they are, at their own pace, individually or in a team. This project, which was carried out using the Blended Learning mode, led to an improvement in the learning of programming. The results show an increase in the levels of motivation and in the students’ learning (with an increase in their final grade), and a reduction in the dropout rate.

ABSTRACT. When the context of a scenario is studied with help of audio, distinct problems appear that entail a challenge for all the acoustic event recognition systems, such as, noise, mixture of different types of sound sources, between others. The methods used for attending these problems generally they are focused over two process; the feature extract process and the classification process. In this paper we propose to use Multiband Spectral Entropy Signatures (MSES) for extracting features from acoustic events with a background of mixture of sounds occurring in a kitchen environment. MSES takes into account the randomness of the signal making it more robust to noise, loudness and spectral flatness. To test our proposal, we created a database of a mix-up of triples from a collection of sixteen real world kitchen sounds using 3dB of signal-to-noise rate. Our benchmark in this work is MFCC feature since it is often used for this issue. In respect to the classification process, we use two similarity distances, cosine distance and Hamming distance. Experimental results indicate that MSES outperforms to MFCC feature in robustness and effectiveness improving the performance of the classification process

ABSTRACT. The aim of this paper is to present a methodology for the control of linear parameter-varying (LPV) systems, focused on the case of linear-time periodic (LTP) systems, where through the application of the extended harmonic domain (EHD) methodology, it is possible to achieve a transformation of an LTP system into an LPV system. A posteriori, it is possible to analyze the stability of the system and then apply a control strategy such as the model predictive control (MPC), which takes advantage of LPV structure. The described methodology is presented in the application to a power electronic converter such as the Boost converter.

ABSTRACT. In this paper a new modulation strategy for the H-bridge neutral point clamped (HNPC) topology is presented. The proposed modulation scheme allows the conventional five levels multilevel inverter to generate a seven levels output voltage waveform, without any changes in the structure of the HNPC topology. For this purpose a modulation scheme based on the typical Level Shift Pulse Width Modulation (LS-PWM) is designed. In order to obtain the seven output voltage levels, the DC-link is split in asymmetric form, that is one of the DC-side capacitor voltage is the double of the other one. Numerical results were obtained for a grid-tied photovoltaic system in order to evaluate the performance of the proposed modulation technique. An efficiency analysis of the proposed modulation strategy is also shown to illustrate the advantage of this scheme.

ABSTRACT. This paper presents the analysis of AC power-electronic-based power systems with distributed generation units, such as microgrids, for stability and resonance analysis. Two case studies are addressed, and the explicit representation of the commutation process is fully considered. In the first case, an islanded controlled microgrid is presented, the resonances in the system are analyzed and their impact on the stability are shown. In the second case, the resonances and harmonic content in an open-loop system are addressed for three different transmission line models, the results are compared between the fundamental frequency model and the commutated model, showing the varied behaviors that can appear considering different line models.

ABSTRACT. Comparative analysis of the performance of a motor drive with different controller strategies to follow speed and torque variations is presented. B'ezier profiles are used to reduce peaks in voltage an current when the motor conditions change. Details on the construction of a 84 pulse Voltage Source Converter are provided to follow amplitude, phase and frequency required to drive a large motor. Very low total harmonic distortion is proved and harmonic spectrums illustrate the use of a power filter is evaded.

ABSTRACT. Over the past years, different methodologies for assessing the operating condition of mechanical and electrical systems have been proposed. In general terms, the problem has been addressed in a separate way. With the new developments in the signal processing field, it should be explored the possibility to develop a methodology that can deal with both types of systems. This paper proposes a new methodology for the condition assessment of the structural condition in mechanical and electrical systems. The proposal uses a texture feature, the homogeneity, estimated using a recently proposed approach. The proposal has been proved using real-life measurements of both a 34-story building and an induction motor. The obtained results show that the proposal can be considered as a solid alternative for condition assessment in monitoring schemes

ABSTRACT. The use of drones in several areas such as agriculture, security, cinema, sports, enjoyment, and rescue task, to name a few, has grown considerably in recent years. Likewise, the use of drones with autonomous flight is common nowadays. During the drone’s flight, especially autonomous flight in forest, the blades of the rotor may be damaged, scratched or bent due to a collision with a branch or object. These types of mishap can cause the blade to become unbalanced, causing the drone to oscillate or, in the worst case, fall, causing further damage. Taking these into account, in this paper a detection of unbalanced blade on a quadrotor UAV by means of sound is proposed. Sound signals are acquired during the takeoff and overing, then analyzed using DWT decomposition and Fourier Transform. The tests were performed using a balanced blade and an artificially unbalanced blade (to simulated a damage). The results show that the proposed methodology is able to distinguish between a balanced and unbalanced blade.

ABSTRACT. This paper presents a new IP core to calculate the FFT in real-time for an FPGA device. The proposed IP is fully configurable within VHDL without any external tool, it is also portable between FPGA brands. The proposed IP implements a radix-2 DIF for sizes of powers of two from 4 up to 65536. In addition, it uses fixed point arithmetics with a configurable number of bits and numerical format. The obtained results show that the IP is fully portable and configurable in low-cost FPGA devices, with a total resources use from 3% to 10% with operating frequency around 100 MHz, giving sampling data rates between 3.5 MSps to 6.2 MSps at 50 MHz.

ABSTRACT. Technological innovations in electrical systems require the development of testing and validation tools that provide a safe environment and allow configuring different operating conditions. In this regard, power hardware-in-the-loop (PHIL) simulation is a suitable tool that interacts with physical components knowing as hardware under test (HuT) according to a mathematical model. In this work, a PHIL simulation for both electrical source analysis and load studies as HuT using linear and nonlinear loads is carried out. It is performed by means of an ideal transformer model (ITM) as interface algorithm along with a feedback stage using digital filtering, where a state-space control is simulated and implemented in a real-time hardware and a voltage source inverter (VSI) is used as a power amplifier. Different loads are used to validate the PHIL implementation such as resistive (R) load, resistive-inductive (RL) load, and a nonlinear load by considering a DC motor. In this work, two HuT are used, a transformer arrangement and a power inverter.

ABSTRACT. In this paper, the design and validation of a model based on neural networks is presented to estimate online the composition of the light component of a batch distillation column for a binary mixture. The validation is carried out by simulation with real data from a distillation process in an EDF-1000 distillation pilot plant for an Ethanol-Water mixture. The obtained results are compared with those of a nonlinear model of a distillation column operating under similar conditions.

ABSTRACT. Noise is present in everyday life, that it is a fact to find it in everything. Depending on the applications, the noise can present or not issues. In sensing process, the noise would be a huge issue when the accuracy of the system is high, that is to say, when the resolution of the sensor is small, e.g., 40 mV/A. In this case, the outputs equivalents to 3< A have a high SNR. If these signals are used in signals processing, depending on its focus, they can provoke malfunctions and false positives. In this paper, a methodology for noise reduction based on the sparse representation of a signal using a dictionary based on DCT and DST is presented. The proposed method is tested with synthetic signals to research its effectiveness, and then it is tested with real signals taken from the current that supply Induction Motors. After the methodology is applied, signals are analyzed to prove that the information contained is preserved. The noise reduction of the current signals was ~30 dB with the Motor under normal operating conditions.

ABSTRACT. In this work the design of a fuzzy observer with sliding modes for DC-DC power electronics converters is presented. The observer is based on a fuzzy Takagi-Sugeno model having two variable premises, inductor current and capacitor voltage. The observer is validated in simulation with a mathematical software analyzing the observer’s convergence in the transient state, under disturbances in the input voltage and in the load.

ABSTRACT. The applications that come from the study of superficial myoelectric signals (sEMG) are increasing, so there are several ways to acquire them. During the development of this paper, a portable prototype of a device was designed and implemented to acquire, visualize, transmit and/or store myoelectric signals using the Raspberry Pi Model 3 B+ together with the Myo Armband. The algorithms for each task were developed in Python due to the versatility offered by this programming language. Several subjects were selected from among the population of ESPOL students, to whom several tests were carried out, considering different movements of the hand to check the correct functioning of the equipment, and the results indicated that the data were acquired successfully. This portable equipment would eliminate the limitations of having a PC and do it in a specific place, as a condition for taking the records of a person's sEMG

ABSTRACT. This paper describes the methodology used for the selection of the best parameters to generate commands in a brain computer interface (BCI), based on a hybrid combination of two paradigms: Steady-State Visual Evoked Potentials (SSVEP) and Imaginary Movement (IM). The state of the art mentions that associated patterns are identifiable from the electroencephalographic signal (EEGS), but all of them mention the need to transform the data in order to recognize the patterns. The protocol and methodology for the extraction of characteristics from the EEGS to each recording is described for both techniques. The Principal Component Analysis was used to select the characteristics that most contribute to the separation of the data from SSVEP. Besides, wavelet decomposition with Independent Components Analysis was used to obtain the characteristic patterns for the considered movement intention. A comparison was made of the efficiencies obtained with different classification methods: neural networks, nearest neighbors, minimum distance and Mahalanobis distance for SSVEP and a classifier based on correlation was proposed for IM. The number of electrodes to be used was also optimized for the use of these two techniques. Using this methodology, the number of electrodes was 50% reduced, resulting in 7 electrodes for both techniques. This tuning methodology provides a systematic analysis of minimal time required for a threshold of 90% of efficiency. In this study case, 4 seconds for IM and 2 seconds for SSVEP were obtained.

ABSTRACT. It is well known that recording electrical signals from the human body is a challenging task due to their nature and its vulnerability to noise effects. This is also the case of the electrogastrographic signal, the electrical activity of the digestive system that can be recorded using surface electrodes on the external wall of the abdomen. This signal is specially difficult to record due to the different signals present in the abdomen that are larger in amplitude and sometimes completely mask the signal of interest. Therefore, it is very important to clean the recordings before any information can be extracted. This paper describes a methodology to segment the signals with useful information, eliminating those segments masked with artifacts that make the signal useless. A database with 50 recordings from healthy volunteers and diabetes type II patients were analysed during three stages: fasting, after drinking water and after eating a caloric meal. The recordings are first filtered with an adaptive high-pass filter, then it is analysed in one second windows to look for attenuations, saturation and drastic changes. A file with labels is generated that contains only the information of useful windows in order to extract the 2.5 minutes segments that provide information. Then, the Discrete Wavelet Transform and the Fast Fourier Transform are used to calculate the percentage of prevalence in the gastric pacemaker (normagastry, taquygastry and bradygastry). This automatic procedure was tested comparing the segmentation made by an expert by visual inspection. It was found that the automatic segmentation, made by the proposed algorithms, recovers 20% more segments than the expert and saves considerable the time spent in the labelling. The prevalence obtained after segmentation is congruent with the previous works reported.

ABSTRACT. Currently diabetes mellitus affects thousands of people around the world, this syndrome is due to hereditary and environmental causes. Beta cells have a very important role in the cause of this condition since they are responsible for generating and secreting insulin into the bloodstream when glucose levels increase. There are several mathematical models that describe their non linear behavior of beta cells. In this research work, we present the analysis of the fractional order model of Pernarowski. This model permits to observe different bursting patterns by modifying only the derivative order compared to the integer-order model, where it is necessary to change the system parameters.