Influence of the zero sequence voltage on the design of a series active filter

This paper discusses a series active power filter (APF) for a three-phase diode rectifier. The series APF reduces the AC side harmonic current which is drawn by the rectifier and generates a constant DC current. The design of the APF depends on the waveform of the compensation voltage which is injected into the network. The paper demonstrates that the compensation voltage can be changed significantly through a zero sequence voltage without influencing the functioning of the filter and the rectifier. Therefore, the zero sequence voltage is a degree of freedom in the design of the APF. Simulation results are shown.