ABSTRACT. This presentation will  talk about the bio-inspired metaheuristics and some of its uses in the solution of complex optimization problems. First, the term “metaheuristic” will be defined and will be indicated in a general manner how they fit inside the so-called “computational intelligence”. Subsequently, a particular class of metaheuristics that have biological inspiration will be described  and some examples of them will be given. The last part of the talk will provide some examples of real world applications of a particular kind of bio-inspired metaheuristics (the evolutionary algorithms).

ABSTRACT. A36 structural steel is used in shipbuilding industry, pipes that transport gas and oil, offshore structures, other type of structures, as well as in electric equipment especially in the structural parts of power transformers such as tank walls, flitch plates, and frames. Its use in these applications has focused the research on the mechanical properties. Therefore, this research is focused on the magnetic properties. The analysis is carried out for three different ranges of operating temperature. Using the experimental Epstein frame method, the behavior of magnetization and the specific losses curves are obtained. Moreover, with the data obtained and using the finite element method, the model of the zone where high current bushings are mounted on a transformer is obtained and the eddy current losses in the tank wall are calculated.

ABSTRACT. In an attempt of lowering their electricity bills, many customers (from residences to big companies) appeal to illegal means, resulting in great losses for energy companies. The most common trick used is making changes to the energy meters circuits, adding new elements to it or by simply damaging parts of it. In this paper, electromagnetic compatibilitys tests are going to be used in order to differentiate modified energy meters from unmodified ones using a nonintrusive method, based on the comparison of their emitted frequency spectrum intensity. This method proved to be very effective, presenting consistent results even when used in open field tests.

ABSTRACT. The squirrel cage induction motor is one of the most used electrical machines in industry. It is then important to have capable and efficient control strategies to operate this machine at the required velocities for the different applications where is used. One of the more frequent used strategies is the scalar control V/F. This control strategy is very easy to implement and its theoretical fundamentals are so subtle that the engineering community has ignored it and has decided to go for more sophisticated, complex and novel control strategies. In this work we try to give a detailed description of this strategy and its performance when applied to a machine, whose parameters are known, to find the limitations and scope of the scalar control.

ABSTRACT. In rotary systems that incorporate elements such as ball bearings and gears, it is common to find operational alterations, due to the aging of these mechanical elements. One of the main effects of such alterations is the shaft’s vibration, which interferes with its speed and position. In this work, a parameters reconfiguration analysis for shaft position control in a Permanent Magnet Synchronous Motor (PMSM) is done. A Direct Torque Control (DTC) system that includes the treatment of oscillating perturbations in the motor’s shaft is proposed and modeled. This model is simulated in Matlab/Simulink, reconfiguring certain parameters of frequency and amplitude, that typically appear with components aging, obtaining an oscillations reduction.

ABSTRACT. This article presents the design and control of a Maximum Power Point Tracking (MPPT) of a small-power Autonomous Photovoltaic Solar System, oriented to the distribution of electrical energy from renewable sources to small towns that do not have the service of the power grid, so it has been considered DC power of solar generation of 6 KW, using MATLAB as a simulation tool. For design validation purposes, a 90W two-axis autonomous photovoltaic solar module and a Buck charge regulator with MPPT control have been built. For the purpose of acquiring solar energy data, a DAQ-USB 6008 from National Instruments and LabVIEW has been used, and for control purposes Arduino Nano v3.0 has been used.

ABSTRACT. Due to the intermittent characteristic of renewable sources, battery storage systems (BSS) play an important role in instantaneous power balance. In isolated microgrids, lead acid batteries are still widely used as storage and their useful life is directly related to the way they operate. The profile of renewable sources contributes to the loss of battery life. One way to mitigate this problem is to use a dual battery storage systems (DBSS), which enable better integration between renewable generation source and storage devices. However, this strategy strongly depends on the characteristic of the renewable source and in the case of tidal stream plants, its benefits have not been evaluated. In this paper, we use a DBSS formed by two storage subsystems with different functions and subjected to different charging/discharging conditions, according to the characteristics of the tidal currents source. A comparison is made between the source of tidal and photovoltaic currents evaluating the benefits of a DBSS microgrid. The Schiffer model to estimate the battery life as a way to evaluate the benefits of the applied strategy was used.

ABSTRACT. In this paper, a methodology to evaluate the repowering of small hydroelectric power plants is proposed. This methodology considers the technical and economic viability of the project. The methodology includes an analysis of the current state of elements of the power plant, such as electromechanical equipment and existing infrastructure. The technical analysis includes the hydrological study, which allows determining the appropriate equipment based on the water flow. On the other hand, financial analysis provides a valuable tool to determine the viability of repowering. The case study is El Amarillo power plant in Portovelo, Ecuador, it is a small hydroelectric power plant, currently abandoned. The modernization of the power plant based on current technology allows the electricity generation from renewable resources, contributing to local development and the reduction of CO2 emissions with an installed power of approximately 3.3MW.

ABSTRACT. The incorporation of electric vehicles will require an adaptation of the infrastructure which should be adapted to the needs of the Plug-in Electric Vehicles (PEV), gas stations and parking lots must be modified to provide a battery charging service that is efficient to satisfy the mobility of its users. This paper seeks a fuzzy logic PEV load coordination scheme for smart parking lots through some input parameters such as: State-of-Charge (SoC), connection time, maximum energy rate, etc., these parameters can determine at what time it is appropriate to charge a vehicle’s battery. The fuzzy logic described in this paper allows assigning a priority score to the PEV by means of rules inferences, although it is difficult to subjectively evaluate which vehicle should be charging first, this can be achieved in a context where only the SoC and the remaining connection time of the load are evaluated. The structure of the system is scalable and flexible, so that more evaluation variables and restrictions can be incorporated to simulate a greater number of operating conditions, the system is built using the Matlab/Simulink® simulation software.

ABSTRACT. This paper presents a nonlinear controller for a quadrotor with a slung load, whose mathematical model is derived using the Euler–Lagrange equations. The aim of the control is to guarantee stability of the quadrotor’s attitude and altitude. The slung load is considered as an additional a disturbance. The control, designed using the Lyapunov tech- niquee, compensates these disturbances and ensure stability. The controller performance is tested through simulations in Simulink.

ABSTRACT. The present article describes the use of controllers, using a profit planner algorithm, to stabilize a mass in a given reference point, using two steel cables and a metal rod, analyzing the catenary behavior of the cable in several points of operation of the system. To obtain a better uniformity of response, a control system was adopted, with reference signals type ramp, to stabilize smoothly and get to the reference quickly, in order to avoid the accelerated start of the three-phase motor and obtain better accuracy in the response of the system. The tuning of the controller is done in several stages, since being a system of non-linear type, proceeds to use the method of extended linearization, adjusting different parameters Kp, Ki and Kd, for the rise or fall of the mass due to the elongation and contraction of the cable. The graphs obtained visualize the solution of the problem and the action of the controllers in the corresponding stages, giving an efficient response to external disturbances, stabilizing the mass in the reference position given in each test performed.

ABSTRACT. This paper deals with faults diagnosis in discrete event systems, which can be represented through Petri net models partially observable. The approach herein presented deletes all the unnecessary information from the incidence matrix of the Petri net, and builds a reduced observable projection using the observable complement of the unobservable part of the net. Using this observable projection and an off-line algorithm the diagnosability of Petri nets using their structure can be characterized. The reduced observable projection that is obtained is used to locate and detect faults. An example is proposed to show the results.

ABSTRACT. A simple wireless charger circuit for mobile phones is presented. The aim of the study is to implement wireless charging on devices not equipped for it. The driver is based on a half bridge inverter and a series-series resonant converter. Experimental results validates the analysis and design and shows the feasibility of the proposal.

ABSTRACT. Preventive medicine requires early detection of diseases in order to begin a treatment that would allow a better life quality for the patients. In the Alzheimer Disease (AD) early diagnosis is key for taking actions that prevent the disease from advancing too quickly. People with AD are normally not aware of the problem when they are in the early stages of the disease. For these reasons, it is important for everybody to have easy access to cheap and fast diagnosis systems. In this paper, the implementation of a simple diagnosis system for AD is described, the system uses Electroencephalograms (EEG) since they are obtained in a non invasive way and have been proved to be useful for the diagnosis of AD. The system extracts features from the EEG to build a feature vector and implements a simple dichotomizer. The tests included 16 individuals suffering from AD and 34 healthy individuals, the results show that the system is functional and has an accuracy similar to state-of-the-art.

ABSTRACT. The description of the pressure variation in the wall of a cylindrical shell, caused by an oscillating acoustic pressure force induced by an ultrasonic wave, is evaluated through equations related to the First Shear Deformation Theory, by means of simulation and computational analysis implemented in a tool based on the Finite Element Method. The simulated structure represents an approximation of an arterial wall, which is radiated by an ultrasonic transducer. This simulation was built in COMSOL 5.3 software, obtaining pressure behavior in the structure of interest, besides a representation of an acoustic pressure field caused in the environment by the wave.

ABSTRACT. Non-Mydriatic fundus cameras are very suitable for teleophthalmology framework, because this type of fundus cameras does not require eye-drop to dilate patient’s pupil to take image, and then image acquisition can be realized without expert such as ophthalmologist. However, in this scheme, automatic and accurate image quality assessment on site is indispensable, because the transmission of low-quality images to the central hospital causes only waste of time. In many cases, low-quality images are useless for reliable diagnostic. In this paper we analyze several generic features for automatic quality assessment of the fundus images taken by wide-view non-mydriatic fundus cameras. The performance of several combination of the generic features extracted from the fundus images are evaluated using different classifiers, such as support vector machine, K Nearest Neighbor (KNN) classifier, decision tree-based classifiers, etc.

ABSTRACT. In this article presents a 5-level multilevel inverter and describes the operation principle using the sinusoidal pulse width modulation technique. The topology includes 4 IGBTs switching devices, 4 complementary, and 2 asymmetrical voltage sources. The control will be carried out by means of digital devices and the performance of the proposed multilevel inverter is confirmed through simulation and experimental results, under different sinusoidal pulse-width modulation techniques.

ABSTRACT. Grid-connected low-power PV systems are begin- ning more and more popular inside the energy market. Such a systems, are commonly installed in residential and small commercial buildings, having as a main objective the reduction of the energy bill. Efficiency is a key word in the design of PV systems since this parameter contributes with economic benefits for the investors. Among low power systems, micro-inverters are designed to inject the generated energy from a single PV panel to the electrical grid. A single photovoltaic panel produces a voltage around 35 V, therefore micro-inverters are generally designed using two stages. First stage boost and regulate the output DC voltage while the second stage produces the injected AC current. Single-phase H-bridge inverter is the basic topology used in the second stage of the isolated micro-inverters. In this paper, a modified hybrid high-frequency H-bridge inverter is proposed using a combination between MOSFET’s and IGBT’s according with the low and high frequency pulse width modulated signals. The proposal is evaluated by means of numerical results and compared with transformerless topologies considering the total harmonic distortion and efficiency as the comparative parameters.

ABSTRACT. This paper presents a DC-DC Cúk converter for transferring photovoltaic energy to batteries. The Cúk converter has the characteristic of having an inductor at the input and an inductor at the output, this allows to reduce the current curl at both the input and the output. This feature is desirable in systems that transfer the electrical energy of the photovoltaic modules to the batteries in order to reduce the current curl. This article presents the analysis and design of the Cuk converter using a methodology based on switching functions. Likewise, the MPPT algorithm of disturbing and observing is applied. The methodology includes a way of sizing passive elements based on the curl factor and the power of the photovoltaic module. The simulation and experimental results validate the analysis and design presented.

ABSTRACT. In this paper the modeling and control design for a back-to-back converter to improve the power quality in microgrid systems are presented. The selected topology is based on the single phase double-boost as a rectifier interfaced with the well-known H-bridge power converter which acts as an inverter. The proposed topology is a linkage between two AC grids with different or equal fundamental frequencies delivering power in a unidirectional way. Both converters have a common DC-Link which is used to store the energy to be transferred from one side to another between the grids. Then the main idea is to transfer active power from the first grid to the second AC grid. The proposed control law to this end consists of three loops which are referred as rectifier-side current control loop, an inverter-side current control loop and a DC-Link voltage regulation loop. The first is designed as a proportional controller plus a bank of resonant filters aimed to mitigate the harmonic content present on the rectifier-side current. The second control loop is composed by a proportional plus resonant controller which delivers a sinusoidal current in phase with the grid voltage. The voltage regulation loop is able to regulate the common DC-Link voltage for both converters in such a way that it maintains a desired value despite of power reference step up and step down changes. This control loop consists of a proportional plus integral controller whose output signal acts as a modulating signal for the rectifier side current reference. In order to evaluate the performance of the controller, numerical simulations are performed.

ABSTRACT. The medium frequency transformers (MFTs) are key components of CD-CD converters, in order to achieve high performance and high efficiency. Also, they are a fundamental part for the development and improvement of renewable energy sources, such as photovoltaic systems and wind farms, as well as solid state transformers and electric vehicles. A high power density, weight reduction and physical dimension are key characteristics in the design of these devices. The increase of the design frequency makes possible a high power density. The weight reduction of the device requires the use of new methodologies and different materials compared with those used in conventional 60 Hz transformers. This article presents an analysis of a MFT (1.75kVA at 5kHz), with a nanocrystalline core. The results of this work show that MFTs with this kind of core have favorable characteristics such as high efficiency and high power density for a medium frequency range in CD-CD converters.

ABSTRACT. This paper is addressed to describe a new methodology for the 2D (Azimuth and Elevation) estimation of the direction of arrival (DOA) of quasi-stationary signals, based on a Khatri-Rao (KR) subspace approach for uniform circular arrays (UCA). The developed methodology is effective on underdeterminated scenarios where the additive spatial noise is unknown, and the SNR is low. To demonstrate the effectiveness and performance of the algorithm, several simulations and tests were performed for different scenarios.

ABSTRACT. In this work, it is designed and implemented a discrete-time sliding mode control algorithm applied to control head's position of the Nao humanoid robot. This is done firstly, by obtaining the direct kinematics through the Denavit-Hartenberg criteria; secondly, the differential kinematics is computed by the relationship between joint velocities and the linear velocity of the two joints; finally, the dynamics model of the head is obtained by using the Euler Lagrange's equations. Once the mathematical model is obtained, it is used a zero-order hold for obtaining the discretization and a block control transformation in order to design the sliding surface, also in discrete-time. To this sliding surface, it is applied the discrete-time sliding mode algorithm to control the angular positions of the Yaw and Pitch joints. The complete closed-loop system is simulated in Simulink/Matlab in order to probe the proposed methodology. To validate the control algorithm, the proposed methodology is implemented in the generic simulation system SimSpark Nao robot, where different tracking references are probed. The results obtained validate the proposed control algorithm applied to the Nao robot.

ABSTRACT. The different types of the detectors have been evaluated to find targets on the sea surface by using recorded videos from a fixed camera placed on the beach, but not with mobile cameras, therefore, in this work recorded videos from a quadrotor are analyzed in order to monitor and detect barely discernible objects on the surface of the sea. The Adaptive Subspace Detector (ASD) and the Modified Adaptive Subspace Detector (MASD) based on the Generalized Likelihood Ratio Test (GLRT) are implemented and compared by video processing by varying parameters such as the size of the analysis window, the number of harmonics and the number of processed images. The numerical and experimental tests allow to make recommendations on which detector to use under certain conditions.

ABSTRACT. A virtual test bench based on the cosimulation of finite element analysis and circuit simulation has been applied to evaluate controllers in three-phase induction motors. A finite element model is used to carry out the electromagnetic analysis of the induction machine. This model has the advantage of considering a precise distribution of induced eddy-currents, the material nonlinearity, space and time harmonics, and torque pulsation. The speed and rotor magnetic flux norm tracking problems are tackled with a nonlinear passivity based controller. The results show the existence of an overexcitation problem in the control action when the motor operates at full load and nominal speed. This problem was not so evident in the state space simulation, which confirms that the use of this cosimulation platform represents a helpful and reliable starting point before experimentally implementing the controller.

ABSTRACT. The research of more efficient power ac-ac converters, such as the matrix converter, a topology that reduces the losses of enegy convertion due to a single stage conversion, provides bi-directional power flow, sine wave in and out, variable power factor both input and output, is obstructed by difficulties of building, replacement of damaged devices and electromagnetic interference (EMI) on an experimental prototype. The trend is given by manufacturing more efficient and smaller converters, where to achieve these objectives it is necessary to experiment with the use of new semiconductor devices and new switching strategies. On the other side, for the manufacture of low-cost converters, it is necessary to make use of cheaper devices and therefore less efficient. This paper reports the development and implementation of a compact and easy-replacement matrix converter, built in four parts: power modules with bi-directional switches, control circuit, measure circuit and filtering, in order to facilitate the replacement of damaged devices and reduce electromagnetic interference problems.

ABSTRACT. A new method, based on binary integer programming, to solve the problem of fault section estimation in power systems is developed in this work.This optimization model is formulated based on a set of minimum covers, subject to logical protection constraints applied by electric power companies. Constraints of this formulation, compares protection relay alarms reported from the SCADA system with the expected states of the protection relay functions allocated in power system. Naturally, the proposed problem is a complex binary integer nonlinear programming model. In order to apply classical optimization techniques, this model is recast as binary integer linear programming model. Numerical results show the effectiveness, applicability and robustness of the presented strategy by using a 7-bus test system.

ABSTRACT. A mathematical model is presented for the estimation of the contribution of biomass to the generation of electricity for a valley as a geographical scope of application. It is considered that a valley has several species that are cultivated during the year and that have by-products of the harvest that we have considered as biomass that can be used for the production of electricity that would benefit the valley's inhabiting community. We have called this integration between population and crops SmartValley, which leads to the use of monitoring, control, management and planning among the different agricultural-energy actors. The cultivation and production of plants shows production variations during the year and throughout the years. For this, the mathematical model has as an essential part the data of usable biomass from which the electricity production estimate is made. A case study has been considered for the present study: a typical valley on the north coast of Peru, where rice crops are quite common, and; they have the potential to be used for electricity generation

ABSTRACT. The increasing incorporation of renewable energy sources with power electronics converters into electric power systems impacts in the grid inertial response. This impact is more severe when conventional generators are replaced for photovoltaic (PV) systems and when the penetration of this renewable source is high. In this paper, the impact of replacing synchronous generators for PV generation systems in a test network is analyzed. Due to PV generation systems cannot provide an inertial response, it is proposed to use a battery energy storage system (BESS) to enhance the grid inertial response under fault conditions. A comparative study is carried out through simulations in Simulink/MATLAB to show the grid inertial response of the test system, varying the number of synchronous generators, PV modules, and BESS.

ABSTRACT. Applications of local systems for power generation connected to the utility power grid require tuning between the phase grid voltage and the voltage synthesized by the converter.The most widely accepted solution to provide tuning between time-varying signals is the use of a Phase-Locked Loop (PLL) system. The implementation of a phase tuner based on a PLL embedded in a digital signal processor (DSP) is presented, this tuning technique is aimed to assist DC-AC inverters of a single phase system of local energy generation for create a sine wave in concordance with the grid. In many cases, the reference signal obtained from the grid voltage is contaminated by harmonics, for this reason, a series of tests are presented in order to demonstrate the robustness of this tuning technique.

ABSTRACT. Currently there is a great opportunity in Mexico since only 3.2% of hydrogen production is done by electrolysis. One of the factors is the high cost of materials and electricity. The first can be dampened by increasing the current density that transits through the electrodes. The study of low cost and affordable materials in the market can boost the development of economical electrolysers and optimal performance. Materials such as AISI 316 steel. The alteration of the surface microstructure, the electrolyte (caustic soda at 20% by weight) and the separation of the electrodes directly affects the electrical consumption. In this study we experimented with different gaps between electrodes (2.8, 4.0, 6.3, 10, 14, 20mm), resulting in the separation of 10 mm as the highest production of oxyhydrogen gas at a lower electricity consumption.

ABSTRACT. This paper proposes a harmonic decomposition approach for modeling and forecasting of time series, with the novelty that a state-space representation of the harmonic content of a non-stationary signal is established from a basic Fourier series analysis. Based on the time series state-space model, which becomes a linear time-varying system, an optimal estimator (Kalman-Bucy filter) is designed to estimate the harmonic content of the signal (time series). The analyzed time series are temperature and wind speed. Once the harmonic model is stated for the time series, the forecast is obtained. Forecasting errors are quantitatively analyzed to evaluate the effectiveness of the proposed methodology.

ABSTRACT. The power transformer is a valuable asset of the electrical system. A damage causes the interruption of electrical service and high repair costs for companies. Therefore, the detection of faults in incipient conditions is essential. In the recent literature Dissolved Gas Analysis (DGA) is the best accepted technique to the diagnosis of incipient faults in power transformers. This paper presents an approach to diagnosis fault by DGA using deep neural network, the drawbacks of the number of training patterns (amount of data) is satisfactory solved with using the Mean Shift algorithm. Likewise, the input and output parameters are conveniently selected, the input parameters being the gas relations established in the IEE60599 standard acting in parallel with a new ratio of proposed gas (Rnew = C2H2 / C2H6) and a binary output. The proposed approach achieved an accuracy of 100%, both in the training and validation process as well

ABSTRACT. Nowadays, induction machines are widely used in various sectors, their robustness allows them to operate even in fault conditions; this can lead to permanent damage to the machine and economic losses as a result of machine replacement and/or production downtime. This reflects the importance of monitoring methods or strategies to detect imminent failures. Bearing Failure can be detected by treating signals such as sound, vibration and/or current. This work is based on the comparison of the following methods: Spectral Analysis and 2 types of Goodness-of-Fit Tests; these methods are performed using Motor Current Signature Analysis. The strategies mentioned above, as well as the comparison of their accuracy, are validated experimentally.

ABSTRACT. A crucial task to maintain the integrity and efficiency of pipelines is the monitoring and early leak diagnosis. This fact has motivated the development of different analytical techniques that have the common objective of performing the leak detection and location task automatically. However, one of the major constraints for the implementation of these techniques in real-world applications is the high cost of data acquisition and transmission systems. Thus, this paper presents the implementation of a leak diagnosis technique, in a wireless electronic low-cost system which has been designed as a prototype and based on Arduino-XBee technology. We have proved it in an experimental pipeline in Mexico and good results have been obtained.

ABSTRACT. The design and implementation of a radio beacon system for cyclists is presented, the system is intended to automatically detect the occurrence of accidents involving head impacts through the helmet, send user’s position data to the cloud through a LoRaWAN network, and finally notify to relatives or friends via SMS. The proposal requires two devices to be used by the cyclist, one adapted to the safety helmet and the other to the bicycle, these maintain Bluetooth Low Energy communication during riding. The first one has a triaxial accelerometer constantly monitoring whether the magnitude present on the helmet has exceeded a threshold value, event that could represent a head impact. The second one integrates a gyroscope, in order to detect abnormal rotations on the bicycle, potentially due to an accident suffered by the user, in addition this device includes a GNSS receiver to obtain global position data and a LoRa transceiver to establish long distance communication with a radio base. The crash detection is triggered only when the specified movement events coming from both devices has happened within a short time window. The experimental functional tests show that implementing distributed signal inputs in the crash detection validation process, in this case, kinematic parameters from the helmet and the bicycle, has a better response than those using only one, essentially because it is more effective to rule out false positives. LoRa technology allows implementation of small, long distance communicating devices, achieving in the applied test the coverage on almost all of the urban area of Cuenca city with a single active gateway, a maximum distance of 7.6km and a packet loss of 18%.

ABSTRACT. The Universal Plug and Play (UPnP) communication protocol has become a standard for communication between devices in the Internet of Things (IoT) family in recently years. The UPnP protocol has facilitated the use of IoT devices in people lives and organization's daily due to the simplicity of use, but since it is a communication protocol that operates with other standardized network protocols, it also has vulnerabilities that can be exploited by a threat and cause a security incident. The files in XML format that the UPnP protocol uses for the identification of the devices having a standard structure and are transmitted in clear text represents a security risk that may compromise the confidentiality, integrity and availability of the devices and an entire services of a corporate network. This article presents a proposal to develop a security tool to protect the identity of the devices as a Smart TV when the UPnP protocol makes use of the XML files in a data network.

ABSTRACT. This paper presents the implementation of web technology to automate a hydraulic process by means of a commercial development board, Raspberry Pi. A web page was designed and the Ethernet standard has been used to stablish the local connection with the input and output ports of the Raspberry board. A program was coded in Python language to receive signals from the limit switch sensors and control the electro valve through a relay module. The valve has two solenoids and requires 24 V DC to commute its position. This valve acts on the hydraulic cylinder to automate the process, which can be understood like an implementation of Indutry 4.0. The hydraulic process was simulated and the implementation with Raspberry Pi has shown successful results.

ABSTRACT. MOSyG: a monitoring system for a germination chamber is developed in this paper. The temperature and humidity parameters can be observed in real-time and controlled using fuzzy control techniques through the integration of the platforms Cloudino-IoT, FIWARE and Grafana. The use of these open-source platforms combined allows to take advantage of cloud computing to sustain, store and analyze the data and to automate the environmental parameters to maintain temperature and humidity levels to create a favorable growth environment. The set-point control performance is illustrated with some experimental results as well as the interconnection of the IoT devices.

ABSTRACT. This paper addresses the development of a system to recover the energy regenerated by Metro trains during their braking stage. The system is based on grid-tied inverters which take the surplus energy and inject it into the grid. The system is validated in a Hardware In the Loop emulation tool. A current control scheme based on the synchronous rotatory frame is utilized to handle the active and reactive powers to be injected into the grid, in order to keep synchronization between the inverter and the grid a DSOGI SRF-PLL algorithm estimates the grid phase in doing so, it is possible to operate under unbalanced grid conditions. To validate the scheme a DSP F28335 with the synchronization and control algorithms is used together with Typhoon HIL 402 which one oversees the grid and the inverter emulation.

ABSTRACT. In this paper, a control scheme for power factor correction (PFC) and output voltage regulation of a AC-DC boost power converter based on average current-mode control is presented. The proposed methodology relies on the design of two feedback loops; A non-linear inner loop for current tracking based on passivity-based control (PBC), as well as, an outer loop to generate a suitable desired value for the current using a PI action on the output voltage an its reference. Also, based on Immersion and Invariance (I&I) theory, an uncertainty estimator is constructed in order to cope with the parametric uncertainties of the modeling process on the power converter. The closed-loop system performance is evaluated through numerical results, where precise regulation, tracking and robust behavior with respect to large unknown load variations are tested successful.

ABSTRACT. In this document the controller for an extended step-down conversion ratio converter is designed and experimentally validated through a laboratory prototype. The converter consists of a buck converter that has a array of capacitors and diodes at the input that enables to extend the step-down voltage conversion ratio. The controller, aimed at output voltage regulation, is based on the averaged model of the converter and consists on voltage and current control loops. The experimental prototype of the converter was built and closed-loop experimental results were obtained.

ABSTRACT. The behavior of nonlinear systems around equilibrium points can be classified into stable or unstable node, stable or unstable focus and saddle point. In most cases, these behaviors can be determined from the poles of the linear approximation around a given equilibrium point. In this paper the analysis and validation of qualitative behaviors of DC-DC power electronics converters around a given equilibrium point is studied. Open-loop as well as closed-loop dynamics are considered. Three different laboratory converter prototypes are used, namely, an interleaved buck, an interleaved boost and a double buck with an LC input filter. These prototypes and analysis were used as an aid to study typical equilibrium point behaviors as an introduction to a nonlinear system graduate course.

ABSTRACT. In this work a control scheme for a Type-4 wind turbine of 30 kW, is presented. The scheme is based on the control of currents obtained from the dq0 framework. The AC/AC power converter is designed based on the generator characteristics. By means of simulations with Matlab and Simulink several results are calculated when the power and the speed in the rotor are changed. The simulated results show that the proposed control has an adequate response to maintain a constant voltage at the load side and control the capacitor voltage and electrical torque in the electric machine in front of some disturbances.

ABSTRACT. There are systems that require the integration of non-linear functions into a linear program for their correct modeling. This document analyzes the situations that may arise when solving an LP to which a non convex function has been introduced as a set of linear constraints. It presents a methodology focused on the solution of the above type of problems. To this end an algorithm for the identification of non convex regions as well as the vertices that delimit the border of each of these zones is proposed. Subsequently, an algorithm to assess the risk of falling into non-feasible solutions is applied. Finally, if required, an alternative solution from the one obtained by the LP solver is returned, ensuring the feasibility of the proposed solution.

ABSTRACT. Given a set of observations an outlier is a measurement that differs significantly from other observations. In a real application, what is sought is to eliminate them since their processing implies statistical errors. Although there are several works that have addressed the outlier detection challenge, in recent works, efforts have been focused to unsupervised scenario because it does not require any a priori knowledge of data distributions and is more attached to reality. Unfortunately, unsupervised approaches have limitations under complex datasets. In order to solve this problem, we propose the use of K-NN rule and fuzzy logic for outlier detection. First, the proposed algorithm is evaluated by using synthetic data; after, the Harvard Unsupervised Anomaly Detection Benchmark Dataset, which consists of several complex data structures based in real-world applications, is used. In comparison with the current works, our algorithm outperforms most previous works for the Harvard Breast cancer dataset dataset (ROC score equal to 0.9980) while for the Harvard Pen Global dataset our algorithm achieves relatively higher accuracy (more accurate than some previous works) and similar results than most accurate algorithms in the current literature.

ABSTRACT. This paper aims to classify mathematical sentences extracted from natural language. Mathematical sentences are collected from oral speeches and written documents for being subsequently stored as a linguistic Corpus. Mathematical sentences refer to operations involving any of the four basic arithmetic operations, addition, subtraction, multiplication and division. In this paper, Hidden Markov Models, HMM, are used for the identification of these basic operations and their classification. Before training the HMM, the linguistic Corpus was cleaned up using the Levenshtein distance. In order to have observable symbols two processes are applied. First, a symbol (label) is assigned to each word found in a sentence so that the length of the sequence of observable symbols is directly related to the number of the words of the sentence. Second, for each sentence the entropy of each word is obtained, aiming to obtain sequences of observable symbols with equal length. After training the models, the tests with HMM were evaluated using the metrics of F-score, accuracy, recall and precision.

ABSTRACT. Currently, software is an important element used in different areas, both in the personal or professional. Therefore, it is required that the software be of quality, that is, that it fulfills the purpose for which it was created and satisfies the client. That's why to develop software, you must follow an engineering approach as well as a discipline, being of special importance the Requirements Management (REQM). In such a way that this work considers the REQM as one of the basic areas of project management, it starts with the requirements to define the "what to build" for both the product and the project. This article presents a software engineering systematic review process, the phases followed, the description of each one of them, as well as its implementation applied to the subject of the techniques and tools of the REQM area in SME’s

ABSTRACT. Optimal and unbiased state estimation in diverse environments is a key problem in many branches of engineering, such as navigation, indoor robot localization, communications, power electronics, etc. However, not each estimator is sufficiently robust when the model and environments are not well specified or undergo temporary uncertainties. This lecture presents the optimal finite impulse response (OFIR) and unbiased FIR (UFIR) state estimators, which are fundamentally more robust than the Kalman filter (KF). A comparative analysis for robustness is provided of the UFIR filter, which ignores the noise statistics and the initial values; the KF, which is optimal but not robust; and the H∞ filter, which is robust by design. The filters are tested for robustness against three main factors: imprecisely defined noise covariances, which exact values are typically unavailable in practice; mismodeling, which occurs when the model does not fit the process; and temporary uncertainties such as jumps in phase, frequency, and velocity, which cannot be modeled in view of the unpredictable nature. It is shown that under the ideal conditions, the KF produces best estimates, which cannot be improved using the H∞ filter. Provided that errors in the model are maximized correctly or overrated and the tuning factor is chosen properly, the H∞ filter performs better than the KF. But an incorrectly chosen tuning factor may bring the H∞ filter to instability and divergence. On the other hand, much smaller efforts are required to find an optimal horizon (a single tuning factor) for the UFIR filter, which therefore may be a better choice for robust estimation. A number of applications are discussed to show better robustness of the FIR approach.