Study on Shunt Active Power Filters with coupled inductors

Shunt Active Power Filters (APF) have been proved useful to compensate current harmonics in power grids. In traditional shunt APF, the passive filter, which serves as the output filter, is usually using uncoupled inductors. In this paper, the coupled inductors are adopted in place of traditional uncoupled ones. And both the equivalent circuit and the coupled inductor´s selecting principle are given in detail. In addition, a decoupling control method is proposed without extra hardware cost. Consequently, the volume of the passive filter could be smaller and its cost could be cut down. Simulation results verify the feasibility and validity of the proposed coupled inductors scheme for shunt APF.