High-Performance Discontinuous Pulse Width Modulation Strategy for 3-level Asymmetric T-NPC Inverter

Discontinuous mode pulse width modulation (DPWM) is commonly used to improve switching losses for three-phase converters. This paper studies the DPWM strategies for the 3-level asymmetrical T-NPC (AT-NPC) inverter. First, a carrier-based DPWM technique with an offset function is introduced. Secondly, a space vector DPWM strategy is proposed based on the three nearest voltage vectors principle. The PWM control performance of the proposed modulation methods is then verified by simulation and experimental results. A detailed comparison between the two methods is also conducted.