An active power filter implemented with multilevel single-phase NPC converters

An active power filter implemented with single phase Neutral Point Clamped (NPC) multilevel converters is presented and analyzed. The proposed active power filter is aimed to compensate medium voltage power distribution systems. To take advantage of the single-phase converter implementation, the proposed active power filter allows for series connection of more than one single-phase converter reaching higher blocking voltage capabilities. Compared with the conventional three-phase NPC topology, the proposed scheme presents lower line to line voltage harmonic distortion as well as an independent control in each phase. At this stage, simulated results confirm the viability of the proposed active power filter and associated control strategy.