An efficient switched-reactor-based static VAr compensator

A new static VAr compensator is presented in this paper. To overcome the problems of large low-order harmonics and slow response associated with conventional thyristor-controlled-reactor based compensators, a pulse-width-modulated (PWM) AC converter is used to control the reactances of switched reactors. Yet unlike the PWM static VAr compensators previously reported in the literature, the proposed compensator has a simpler structure and its gating signals are easier to implement. Moreover, it does not require synchronization with the AC mains. The proposed concept was verified through a 1 kVAr prototype and the measured experimental results prove that either leading or lagging reactive power can be achieved through simply duty cycle control