Abstract

A reactive power compensator implemented with three single phase NPC converters is presented and analyzed in this paper. The proposed topology, compared with the conventional three-phase NPC topology, presents the advantages of increasing the number of levels at the output line to line voltages with an independent control in each phase, suitable for unbalanced current compensation. Two independent control schemes based on the state-space model are proposed: one for power factor correction and DC link voltage (decoupled), and the second one for keeping the voltages across the dc electrolytic capacitors balanced (modifying the middle point of the carrier signals). Simulated preliminary results confirm the theoretical considerations. ©2010 IEEE.