AN EFFICIENT SWITCHED-REACTOR-BASED STATIC VAR COMPENSATOR

A new static var compensator is presented in this paper. To overcome t he problems of large low-order harmonics and slow response associated with conventional thyristor-controlled-reactor based compensators, a p ulse-width-modulated (PWM) ac converter is used to control the reactan ces of switched reactors. Yet unlike the PWM static var compensators p reviously reported in the literature, the proposed compensator has a s impler structure and its gating signals are easier to implement. Moreo ver, it does not require synchronization with the ac mains. The propos ed concept was verified rough a 1-kvar prototype and the measured expe rimental results prove that either leading or lagging reactive power c an be achieved through simply duty cycle control.