A Hybrid Optimization Approach to Design Optimally Tuned PID Controller for an AVR System

The Automatic Voltage Regulator (AVR) system is one of the main controls used in power systems to keep the terminal voltage within the specified range at the generator output. It is aimed to improve the dynamic performance and minimize the steady state error by using different controllers in the AVR system. Optimization algorithms are widely used to optimally tune the parameters of the controller. In this study, Symbiotic organism search (SOS), Particle swarm optimization (PSO) and Whale optimization (WO) algorithms are used to tune the parameters of a PID controller designed for an AVR system. For each algorithm, transient response analysis of the AVR system is examined and performance comparison is made. In addition, PSO-SOS hybrid optimization approach is proposed to reduce the time required for optimization while achieving the same transient response characteristics. The proposed hybrid structure is also compared with the optimization algorithms used alone in terms of both required time and transient response performance. It is concluded that the SOS algorithm provides better results than WO and PSO algorithms. In addition, with the proposed hybrid algorithm the same transient response characteristics are achieved in a shorter time than the SOS algorithm.