Anbarasi S , Muralidharan S
This paper deals with an optimal tuning of Proportional Integral Derivative (PID) controller for both Load Frequency Control (LFC) and Automatic Voltage Regulation (AVR) of interconnected power system using Bacteria Foraging Optimization Algorithm (BFOA). As constancy of frequency and voltage are important factors in determining the quality of power supply, the control of active power and reactive power is vital to the satisfactory performance of power system. The real power and frequency is controlled by LFC and the reactive power and voltage is controlled by AVR. Minimization of Integral Time Square Error (ITSE) is taken as the objective function for both LFC and AVR. Various measuring indices like maximum peak, peak time, settling time and the final settling state error are considered as the performance measures for analyzing the transient characteristics of LFC and AVR. The robustness of the system is also examined by applying variable load changes to a system instead of fixed step change in load. The simulation results of the proposed BFOA tuned PID controller is compared with Non Controller System (NCS), Ziegler-Nichols tuned Proportional Integral (ZNPI) controller, Ziegler-Nichols tuned PID controller (ZNPID) and Integral controller. The comparative analysis clearly reveals that the transient performances and the robustness are much improved with the proposed approach over others.