Hardware implementation of a novel, reduced rating active filter for 3-phase, 4-wire loads

This paper presents the hardware results of a new active filter topology with reduced VA rating for 3-phase, 4-wire loads. The scheme consists of a single-phase inverter connected between the zig-zag transformer neutral and the utility neutral in addition to a three-phase inverter connected to the delta winding of the zig-zag transformer. Compared to other reported schemes, the inverter VA rating in this scheme is reduced by a factor of six. This reduction in the inverter VA rating is mainly due to the zero-sequence current inverter having a low VA rating. The equations for this active filter are derived. The simulation results are verified by means of experimental results from a proof-of-concept prototype.<>