Hybrid PID-LQR Controller for Dynamic Response and Stability Ehancement of Synchronous Generator’s AVR System

Abstract

The delay in transition from transient to steady-state of the exciter field dynamic is considered a potential cause of inefficiency in providing stable terminal output voltage for a synchronous generator. One of the consequences is high overshoot in the synchronous generator’s output voltage. This can adversely impact on the performance of connected load to the generator such as electric motor. Proportional, Integral, and Derivative based Linear Quadratic Regulator (PID-LQR) models were designed to address this problem. The system is a hybrid control strategy designed to enhance the voltage stability in the output of Automatic Voltage Regulator (AVR) control system exciter based synchronous generator. Simulation tests in MATLAB indicated that PID+I-LQR reduced the system overshoot from 60.9547% to 1.1524%. This is 98.1 % improvement in system overshoot and stability. A comparison of the designed PID-LQR based controllers with other control systems revealed their superiority in offering smooth and better stability including convergence to stable state for the generator’s terminal voltage profile except LQI and PID+PD-LQR.