The configuration of main circuit and control strategy for active power filter in three-phase four-wire system

The authors examine how to construct an active power filter to suppress the harmonics in three-phase four-wire system. In this paper, two type of main circuits and control strategy for active power filter are introduced. The results of experiment and simulation indicate that harmonics, negative sequence and zero sequence current in three phase four wire system could be compensated by both two types of main circuits.