3 phase switch mode AC voltage controller with low THD and high power factor

Two new schemes of 3 phase AC voltage controller are proposed. The proposed AC voltage controllers are based on Buck switch mode topologies. The proposed AC-AC converters have the advantage of input current shaping that provides low input current total harmonic distortion (THD) and high input power factor compared to the conventional AC voltage controllers. Moreover, only a single control switch is necessary for the AC-AC conversion compared to 6 thyristors in their conventional counterparts. The reduction in switch reduces switching loss and a simpler control circuit suffices. Open loop sliding control has been employed for the control of the proposed AC voltage controllers.