State-feedback control of a voltage source inverter-based STATCOM

STATic synchronous COMpensator (STATCOM) which is used for reactive power control, has the capability for voltage regulation of grid voltage at the point of common coupling (PCC). This is achieved either by injection or absorption of certain amount of reactive power. This control method is efficiently faster in tackling the voltage fluctuating problems[1]. Based on inverter configuration there are two types of STATCOM: Voltage source inverter (VSI) - based and current source inverter (CSI)-based STATCOM[2]. The closed loop feedback controller can be designed to meet different objectives. Conventional Proportional Integral (PI) controllers produce satisfactory response, provided the parameters kp and ki are well tuned. State feedback controller using the d-q reference frame can be designed to give a satisfactory dynamic response. In this paper, state feedback control method is proposed for VSI based STATCOM. Simulation results using MATLAB/Simulink indicate superior dynamic response with the proposed controller.