Wanderson R. H. Araujo

Firing angles optimization for Switched Reluctance Generator using Genetic Algorithms

This paper reports on a Switched Reluctance Machine (SRM) operating as generator excited through external power source. This device provides DC voltage output through its power converter. Parameters such as rotor speed, excitation voltage and firing angles interferes directly on the output voltage. Thus, many strategies have been studied and developed by scientific community in order to control the output voltage or achieve its maximization. This work proposes a driving strategy applied to the SRM that consists in obtaining the optimal firing angles in order to maximize the output voltage for given rotor speed and excitation. Simulations are presented for results analysis.

Heuristic and deterministic strategies applied on a PID controller tuning for speed control of a DC motor

This paper reports on a PID controller for speed control of a DC motor. The controller parameters were obtained through optimization methods employing heuristic and deterministic strategies. This methods were applied on a simulation model in order to verify which one provides better control results.

Calculation of sensitivity index using one-at-a-time measures based on graphical analysis

This work proposes different methods to calculate the sensitivity of system parameters based on graphic analysis. From percentages variations in base values of the parameters, one-at-a-time measures are taken to the construction of a graph that expresses the impact on the output caused by variations in the inputs. Two case studies are proposed, with simulated and experimental data, in which the proposed methods are applied and compared based on the values of the sensitivity indices for ranges of interest. All methods confirm quantitatively the most sensitive variables and the choice of one of the methods depends on the characteristics considered relevant for analysis, i.e., degree of sensitivity of a parameter in relation to another, the behavior of the curve and presence of peaks.

Increasing efficiency of the switched reluctance generator using parametric regression and optimization methods

In this paper the switched reluctance generator (SRG) is explored considering the improvement of its efficiency. This machine generates a DC power that is directly related to input driving parameters. Simulation results are presented bringing a case study of parametric regression to track the best efficiency for any input parameters: excitation voltage and turn off angle. A method known as parametric regression is applied along with deterministic optimization in order to find an equation that provides the driving parameters so the machine can generate DC power associated to high efficiency.

Switched reluctance generator efficiency improvement for wind energy applications

Considering the actual environmental appeal due to excessive consumption of fossil fuels, is relevant the research and development of green power sources in order to conserve the natural resources. Wind energy has become a target of researches and highlights a clean energy scenario. Electrical machines have its reversibility and, operating as generators, can be useful for wind energy aaplications. The switched reluctance generator (SRG) has several advantagens for this application. In this paper, simulation results are presented for a SRG considering its driving. Optimization methods are applied in order to maximize its generated power increasing efficiency as well.

Parametric regression methodology and optimized control for DC motor

This paper presents a speed control for a DC motor. Despite the unknown parameters of the plant to be controlled, these parameters are found using a system identification method. The methodology implemented in this study is known as parametric regression and is based on an optimization technique. This optimization, through its fitness function, allows to find the system characteristics in order to make possible the system control. This control is applied to the DC motor speed through a cascade PI controller, acting on the motor current. Besides, the controller parameters are found through deterministic optimization technique, using the Quasi-Newton method. Simulation and experimental results are presented in order to validate the study and make possible the control of an unknown parameters system.

Speed control for direct current motor using optimization tuning for PID controller

This paper proposes speed to control a the direct current motor (DC motor) containing a PWM signal as input. Through tuning and motor data, a real system can be modeled. Tests are performed in real system to develop a simulation environment. Thus, it is possible to perform PID control by adjusting the gains by the classical Ziegler-Nichols method and then, to compare the results using deterministic optimization method.

Comparative analysis between PI and fuzzy controllers applied to a workbench with an induction motor

This paper presents experimental and simulation results for an induction motor operating with PI (proportional and integral) and Fuzzy speed controllers. This results aim to stablish a comparative analysis between both controllers regarding steady state and transient speed behaviour, just like perfomance under disturbances. To collect the results tests were made in a workbench integrated by several elements, including an induction motor. The workbench development is presented as well.

Regulação de velocidade do motor a relutância chaveado empregando controlador fuzzy

Este artigo apresenta o motor a relutância chaveado, suas caracteristicas, operacao e acionamento e como este dispositivo se comporta dinamicamente quando sua velocidade e regulada por um controlador Fuzzy. A natureza eletronicamente chaveada do acionamento deste tipo de maquina eletrica proporciona elevados niveis de nao linearidade para o dispositivo. Desta forma, controladores de velocidade convencionais como o PID muitas vezes apresentam dificuldades operacionais no que diz respeito ao seu projeto e ajuste de parâmetros para obtencao de desempenhos satisfatorios. Portanto, faz-se necessaria a busca por controladores alternativos que garantam a regulacao de velocidade da maquina quando operando como motor mesmo sobre a influencia das caracteristicas de acionamento chaveado presentes no acionamento. Neste artigo, a simulacao de um motor a relutância chaveado de 60 kW e realizada de forma a verificar seu comportamento dinâmico mesmo com a insercao de perturbacoes.