Common-Mode Voltage and Neutral-Point Voltage Fluctuation Suppression in Ten-Switch Three-Phase Three-Level Inverter Using Space-Vector Modulation

Abstract

Space vector pulse-width modulation (SVPWM) provides a new method to improve the performance of the coupled ten-switch three-phase three-level inverter (TP-TLI). However, it suffers from high common-mode voltage (CMV) and unbalanced neutral-point voltage (NPV). To solve this problem, a CMVR_SVPWM with reduced CMV and controlled NPV is proposed in this paper. The CMV reduction is achieved by using suitable vectors with lower CMVs and sequences. The amplitude of CMV can be suppressed to 50% of the previous proposed strategies for the ten-switch TP-TLI. By enhancing the dwell time of the desired small vector in each region, the NPV can be balanced while maintain the almost same output quality. A 3-kVA experimental prototype is built up to verify the feasibility and performance of the proposed modulation and control strategies.