OPTIMAL TUNING OF PID TYPE STABILIZER AND AVR GAIN USING GSA TECHNIQUE

In this paper, a Problem of simultaneous and coordinated tuning of the PID type Power System Stabilizer (PSS) and Automatic Voltage Regulators (AVR) gains in a Single-Machine connected to Infinite- Bus (SMIB) power system is invastigated. The problem of robustly stabilizer parameters and AVR gain tunning is formulated as a nonlinear optimization problem according to the time domain-based objective function for a wide range of operating conditions and is solved by the Gravitational Search Algorithm (GSA) for improvement of power system low frequency oscillations. The GSA optimization technique is simple, robust and capable to solve difficult combinatorial optimization problems. It simulates the masses cooperate using a direct form of communication through gravitational force and has a strong ability to successful control the local search and convergence to the global optimum solution. The effectiveness of the proposed method is tested on a SMIB power system through the nonlinear time domain simulation and some performance indices in comparison with the some version of PSO based approaches to illustrate its robust performance. Results evaluation indicate that the proposed GSA based coordinated PID type stabilizer and AVR achieves good robust performance for wide range of system operation conditions and is superior to the other methods.