Optimization of the Pulse-Width-Modulation Strategy for Three-Level Inverters with Reduced Power loss

Junction temperature is the main factor affecting the lifespan of insulated-gate bipolar transistor (IGBT). In order to improve the lifespan of three-phase three-level neutral-point clamped (3P-3L-NPC) inverters, this paper proposes a new pulse width modulation (PWM) strategy that reduces inverter power loss based on clamping current. Compared to the traditional space vector pulse width modulation (SVPWM), the proposed method reduces the IGBT junction temperature while ensuring excellent control performance. This will lead to an improved lifespan of 3P-3L-NPC inverter. Furthermore, the proposed PWM strategy maintains the neutral point voltage balance in a wide modulation range. The efficacy of the proposed method is verified by simulation and experimental results.