Fuzzy logic controller parameter optimization using metaheuristic Cuckoo search algorithm for a magnetic levitation system

The main benefits of fuzzy logic control (FLC) allow a qualitative knowledge of the desired system’s behavior to be included as IF-THEN linguistic rules for the control of dynamical systems where either an analytic model is not available or is too complex due, for instance, to the presence of nonlinear terms. The computational structure requires the definition of the FLC parameters namely, membership functions (MF) and a rule base (RB) defining the desired control policy. However, the optimization of the FLC parameters is generally carried out by means of a trial and error procedure or, more recently by using metaheuristic nature-inspired algorithms, for instance, particle swarm optimization, genetic algorithms, ant colony optimization, cuckoo search, etc. In this regard, the cuckoo search (CS) algorithm as one of the most promising and relatively recent developed nature-inspired algorithms, has been used to optimize FLC parameters in a limited variety of applications to determine the optimum FLC parameters of only the MF but not to the RB, as an extensive search in the literature has shown. In this paper, an optimization procedure based on the CS algorithm is presented to optimize all the parameters of the FLC, including the RB, and it is applied to a nonlinear magnetic levitation system. Comparative simulation results are provided to validate the features improvement of such an approach which can be extended to other FLC based control systems.Peer ReviewedPostprint (published version

A comparison of fuzzy-based energy management systems adjusted by nature-inspired algorithms

The growing energy demand around the world has increased the usage of renewable energy sources (RES) such as photovoltaic and wind energies. The combination of traditional power systems and RESs has generated diverse problems due especially to the stochastic nature of RESs. Microgrids (MG) arise to address these types of problems and to increase the penetration of RES to the utility network. A microgrid includes an energy management system (EMS) to operate its components and energy sources efficiently. The objectives pursued by the EMS are usually economically related to minimizing the operating costs of the MG or maximizing its income. However, due to new regulations of the network operators, a new objective related to the minimization of power peaks and fluctuations in the power profile exchanged with the utility network has taken great interest in recent years. In this regard, EMSs based on off-line trained fuzzy logic control (FLC) have been proposed as an alternative approach to those based on on-line optimization mixed-integer linear (or nonlinear) programming to reduce computational efforts. However, the procedure to adjust the FLC parameters has been barely addressed. This parameter adjustment is an optimization problem itself that can be formulated in terms of a cost/objective function and is susceptible to being solved by metaheuristic nature-inspired algorithms. In particular, this paper evaluates a methodology for adjusting the FLC parameters of the EMS of a residential microgrid that aims to minimize the power peaks and fluctuations on the power profile exchanged with the utility network through two nature-inspired algorithms, namely particle swarm optimization and differential evolution. The methodology is based on the definition of a cost function to be optimized. Numerical simulations on a specific microgrid example are presented to compare and evaluate the performances of these algorithms, also including a comparison with other ones addressed in previous works such as the Cuckoo search approach. These simulations are further used to extract useful conclusions for the FLC parameters adjustment for off-line-trained EMS based designs.This work is part of the projects 2019-PIC-003-CTE and 2020-EXT-007 from the Research Group of Propagation, Electronic Control, and Networking (PROCONET) of Universidad de las Fuerzas Armadas ESPE. This work has been developed with the support of VLIR-UOS and the Belgian Development Cooperation (DGD) under the project EC2020SIN322A101. This work has been partially supported by the Spanish Ministry of Industry and Competitiveness under the grant DPI2017-85404 and PID2019-111443RB-100.Peer ReviewedObjectius de Desenvolupament Sostenible::7 - Energia Assequible i No ContaminantPostprint (published version

An energy management system design using fuzzy logic control: smoothing the grid power profile of a residential electro-thermal microgrid

© 2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.This work deals with the design of a Fuzzy Logic Control (FLC) based Energy Management System (EMS) for smoothing the grid power profile of a grid-connected electro-thermal microgrid. The case study aims to design an Energy Management System (EMS) to reduce the impact on the grid power when renewable energy sources are incorporated to pre-existing grid-connected household appliances. The scenario considers a residential microgrid comprising photovoltaic and wind generators, flat-plate collectors, electric and thermal loads and electrical and thermal energy storage systems and assumes that neither renewable generation nor the electrical and thermal load demands are controllable. The EMS is built through two low-complexity FLC blocks of only 25 rules each. The first one is in charge of smoothing the power profile exchanged with the grid, whereas the second FLC block drives the power of the Electrical Water Heater (EWH). The EMS uses the forecast of the electrical and thermal power balance between generation and consumption to predict the microgrid behavior, for each 15-minute interval, over the next 12 hours. Simulations results, using real one-year measured data show that the proposed EMS design achieves 11.4% reduction of the maximum power absorbed from the grid and an outstanding reduction of the grid power profile ramp-rates when compared with other state-of-the-art studies.Peer ReviewedObjectius de Desenvolupament Sostenible::7 - Energia Assequible i No ContaminantPostprint (published version

Control directo al par y control de campo orientado para un motor síncrono de imanes permanentes

Context: The permanent magnet synchronous motors (PMSM) have rapidly improved their performance in terms of power density, efficiency, and better dynamics, thanks to the technologies used in them, such as: the control technique and the drive circuit technology. A PMSM can operate both as a motor and as a generator. In addition, they stand out for having a low maintenance, since unlike other types of engines the PMSM does not have collector rings or brushes. The control algorithm that is generally used in this type of motor is a vector control, which is divided into Direct Torque Control (DTC) and Field Oriented Control (FOC). Method: The computational platform where the simulations are carried out is MatlabR software (R2017a) Simulink 8.9, where predetermined blocks and program functions are used for the DTC and FOC vector control diagrams. Results: Regarding the electromagnetic torque control, FOC presents higher ripple than the DTC, so that, it is concluded that the DTC has greater torque control in relation to the FOC. Regarding to the magnetic flux control, according to the obtained values, the DTC has better control performance than the FOC. For speed control, both the DTC and FOC control have a fast response to disturbances; however, the DTC has a fast control response when the PMSM starts moving from rest, which means that the DTC has a faster response in the transient state and when the engine is in motion FOC has better control performance to disturbance. Conclusions: When analyzing the most important aspects to determine which control technique is effective, it is concluded that the DTC control technique has greater effectiveness with respect to the FOC control technique. However, it is worth mentioning that the two control techniques are widely used in the industrial sector for driving electric motors, so that, the selection any of these techniques Will depend on the process to be carried out.Contexto: Los motores síncronos de imanes permanentes o Permanent Magnet Synchronous Motor (PMSM, por sus siglas en inglés) han mejorado rápidamente su rendimiento en cuanto a la densidad de potencia, eficiencia y mejor dinámica, gracias a los procesos de tecnologías empleadas en ellos tales como: la técnica de control y la tecnología de circuitos de accionamiento. Un PMSM puede operar tanto como motor y como generador, además se destacan por tener un reducido mantenimiento, ya que a diferencia de otro tipo de motores los PMSM no presentan anillos colectores ni escobillas. El algoritmo de control que se emplea generalmente en este tipo de motores es un control vectorial, divido en Control Directo del Par (DTC) y Control de Campo Orientado (FOC). Método: La plataforma computacional donde se realizan las simulaciones es en el software Matlab (R2017a) Simulink 8.9, donde se utilizan bloques predeterminados y funciones programas para los diagramas de control vectorial DTC y FOC. Resultados: En cuanto al control del par electromagnético, FOC presenta mayor rizado que el DTC, por lo que se determina que el DTC tiene mayor control de par en relación al FOC. Para el control del flujo magnético, de acuerdo con los valores obtenidos, el DTC tiene un mejor control que el FOC. Para el control de velocidad, tanto el control DTC como FOC tienen una rápida respuesta ante perturbaciones, sin embargo el DTC tiene un tiempo de respuesta menor cuando el PMSM se pone en movimiento desde el reposo, es decir que el DTC tiene una respuesta rápida en el estado transitorio y una vez que el motor se encuentra en movimiento, ante perturbaciones como la disminución de velocidad el FOC tiene mejor control. Conclusiones: Al analizar los aspectos más importantes para determinar cuál técnica de control es efectiva, se concluye que la técnica de control DTC tiene mayor efectividad de acuerdo con la técnica de control FOC, sin embargo, cabe mencionar que las dos técnicas de control son ampliamente utilizadas en el sector industrial en el accionamiento de motores eléctricos por lo que la selección de dichas técnicas dependerá del proceso a realizar.

Controlador en Modo Deslizante para Sistemas Fotovoltaicos Conectados a la Red Eléctrica

Se describe el análisis, modelamiento y diseño de un lazo de control para sistemas fotovoltaicos (PV) conectados a la red eléctrica. Se aborda el modelado de un panel fotovoltaico; el diseño de un convertidor elevador (Boost) y su lazo de control mediante un controlador proporcional-integral PI de corriente y un controlador en modo deslizante; y finalmente el diseño de un inversor DC-AC de una fase. Se realiza una descripción de la dinámica del convertidor Boost y de las ecuaciones para el diseño del controlador en modo deslizante y del inversor de una sola fase. El sistema propuesto ha sido simulado utilizando las herramientas de la librería SimPowerSystems de Matlab/Simulink

Analysis of signal processing techniques commonly used for broken bars detection on induction motors

The fault detection of electric motors has been widely studied due to the importance of these devices at industrial level. This work presents the analysis of different signal processing techniques commonly used for broken bar detection of three-phase induction motors. Fast Fourier Transform (FFT), Hilbert Transform (HT), and Wavelet Transform (WT) are analyzed to obtain the motor current signal characteristics of healthy and faulty motors. The main advantages and drawbacks of each processing technique applied for broken bar detection of induction motors are presented in this study. The performance evaluation of each technique is carried out in the three-phase induction motor test bench at Universidad de las Fuerzas Armadas ESPE, Sangolquí-Ecuador.La detección de fallas de motores eléctricos ha sido ampliamente estudiada debido a la importancia qu e presentan estos dispositivos a nivel industrial. Este trabajo presenta el análisis de diferentes técnicas de procesamiento de señales que son comúnmente utilizadas para la detección de barras rotas de motores de inducción trifásicos. Se analizan la Transformada rápida de Fourier (FFT), la Transformada de Hilbert (HT) y la Transformada Wavelet (WT) para obtener las características de la señal de corriente de motores sanos y defectuosos. En este estudio se presentan las principales ventajas y desventajas de cada técnica de procesamiento de señal cuando es aplicada para la detección de barras rotas en motores de inducción. La evaluación del desempeño de cada técnica se lleva a cabo de manera experimental a través de un banco de pruebas desarrollado por la Universidad de las Fu erzas Armadas ESPE, Sangolquí - Ecuado

Seismic and Tsunami Risk Analysis for Installing Resilient Power Systems Based on Isolated Microgrids on Buildings: The Case of Puerto Ayora in Santa Cruz Island, Galapagos

Due to their geographical condition and worldwide environmental protection policies, the Galapagos Islands must opt for implementing clean energy infrastructure considering natural hazard effects that can directly affect the resilience of community residents. Santa Cruz Island is part of this archipelago, with rich biodiversity in flora and unique fauna. This study proposes identifying earthquake and tsunami risk assessment components on the island, such as the infrastructure vulnerability of Puerto Ayora, the central city of Santa Cruz Island. The FEMA P-154 and FEMA P-646 methodologies are used to classify buildings for technically installing microgrids based on photovoltaic generation systems. For this purpose, maps and data from state entities are used in combination with catalogs from development and land use planning, Software for Geoprocesses and virtual tours, and cadastral information provided by the Decentralized Autonomous Government (GAD) of Santa Cruz to develop techniques that offer a risk index to identify buildings that could sustain seismic and tsunamic loads. The study exposes alarming results that would prevent the installation of photovoltaic generation systems on the buildings’ roofs. Consequently, a more detailed field study is recommended to contrast the reported analysis to implement mitigation strategies accordingly. Finally, geoprocesseced maps are presented, in addition to general installing recommendations for the photovoltaic system’s infrastructure