Optimum design of PID controller in AVR system using intelligent methods

Abstract

In this paper optimal design of Proportional-Integral-Derivative (PID) controller parameters in an Automatic Voltage Regulator (AVR) system has been considered. In many articles, transfer function of the AVR system has considered being linear, but in this work we applied amplifier limitation block to consider nonlinear conditions. In this way, we would have more realistic results. In literatures, different criteria have been proposed for evaluating the performance of control systems. In this study, two performance criteria that mostly used in evaluating performance of the PID controller are employed to the proposed AVR system. By comparing the step responses of the two criteria, one of them is chosen as the best criterion for performance evaluation of the PID controller in non-linear conditions. Two optimization algorithms namely Shuffled Frog Leaping (SFL) and Particle Swarm Optimization (PSO) are applied for determining the optimal PID controller parameters in an AVR system with respect to minimizing the chosen criterion. Finally, the performance and the robustness considerations have been involved in order to show the stability and efficiency of the system.