An Asymmetric Topology of Three-phase Active Power Filter

An asymmetric topology suitable for three-phase active power filter is proposed. The topology combines a passive filter with a low-power active filter to decrease the capacity and system losses of the voltage inverter (VSI) . It consists of a three-phase bridge, a two-phase dual-resonant LC passive filter and a phase coupled inductor. By reducing the number of devices, the topology design scheme explores the impact of the changes of APF device parameters, which will affect the compensation effect of APF. Finally, a control strategy based on virtual capacitor voltage compensation is proposed to control the system effectively. Simulation and experiments show that the topology and control strategy proposed are feasible.The scheme of this topology and its control strategy can reduce the number of devices and be used in combination with traditional symmetric control strategies, which is easy to be implemented in engineering.