Optimal design of PID controller for AVR in a multi machine power system using modified PSO and fire fly optimization technique

The stability of power system when subjected to disturbances is one of the most important challenges. The Automatic voltage regulator (AVR) is used to enhance the performance of power system due to its acceptability to reduce damping. In this work the problem is formulated as a single objective optimization function to tune the AVR parameter gains of the PID controller. Here the firefly optimization algorithm which is found robustly for this type of problems is selected as a tool to find the optimum solution. Comprehensive simulations are carried out on a four machine power system under various operating conditions. The results are obtained under different fault conditions with FF optimization technique and compared the same with MPSO. At last it is observed that the FF technique performs better in damping the overshoot and settling time.