Shunt active power filter with improved dynamic performance

This paper describes a shunt active power filter (APF) with improved dynamic performance. When the value of load current changes rapidly, the typical APF transient response is too slow, and the line current suffers from dynamic distortion. This distortion causes an increase in harmonic content in the line current, which is dependent on a time constant. The APF control current dynamics is dependent on the inverter output time constant consisting of APF output inductance and resultant impedance of load and mains. In the proposed circuit transient performance of APF is improved using a modified output inverter. According to this modification the APF dynamics are improved. The Matlab simulation results of a modified APF are also presented in the paper.