New virtual space vector modultation scheme to eliminate common-mode voltage with balanced neutral-point voltage for three-level NPC Inverters

摘要

This paper proposes a new virtual space vector modulation (VSVM) scheme that can eliminate the common-mode voltage (CMV) for three-level neutral-point clamped (NPC) inverters with balanced neutral-point voltage. The proposed VSVM scheme is based on the virtual space vector concept, which constructs the virtual vectors from the original medium vectors to achieve zero CMV. Moreover, the neutral-point voltage is balanced because the new virtual vectors keep the average neutral-point current to be zero. Thus, the size of the dc-link capacitors can be significantly reduced. The simulation results are given to verify the effectiveness of the proposed VSVM scheme.