A VARIABLE STRUCTURE VAR STABILIZER FOR POWER-SYSTEM CONTROL

The paper presents the design of a variable structure static VAR stabilizer using a sliding mode control technique. The static VAR compensator (SVC) uses a linear voltage regulator with auxiliary stabilizing signals through a variable structure switching system. The sliding mode control constrains the system motion to a state trajectory, and provides greater robustness to plant parameter variations than classical control schemes. Transient simulations of a typical power system are performed for two alternative locations of the SVC, namely, the generator terminal and the load bus terminal. Also, a nonlinear load is connected to the SVC bus to highlight the effectiveness of variable structure control for variations in load indices.