Three-phase Active Power Filter with T-NPC Type Inverter

The paper presents an analysis of a three-phase active power filter (APF). The focus was on selecting the appropriate output filter for APF with the T-NPC inverter. The contents of switching frequency harmonics in the output currents for other inverter topologies and various output filter structures were compared. The comparison was carried out using simulations in the LTspice ® environment. As a final result, the structure of the LCL filter was proposed for the assumed parameters of the APF system.