Stability of Multi-Machine Power System by used LQG Controller

This paper has been designed optimize feed-back controller for dynamic response of the power systems. The power system consists of the infinite bus through a transmission line supplied by a synchronous machine and also multi machine power system. The effect of two control signals fed to the voltage regulator and the mechanical system is investigated. Robust Linear quadratic Gawssian (LQG) control technique based power system stabilizer is developed for excitation system control and the mechanical system control. The proposed robust LQG-PSS is simple, effective, and can ensure that the system is asymptotically stable for all admissible uncertainties and abnormal operating conditions. To validate the effectiveness of the proposed power system stabilizer, a sample power system consists of multi machine and single machine are simulated and subject to different disturbance and parameter variations. Kalman Filter is used for compound with LQR to get robust LQG control. The results prove the robustness and powerful of proposed LQG controller stabilizer than LQR controller in terms of fast damping response and less settling time of power system states responses. Key-word:LQR controller , LQG controller, power system stabilizer and multi-machine power system