Device Loss Distribution Analysis of Neutral-Point Clamped Three-Level Inverter With 240CPWM

This paper introduces a 240°-clamped PWM (240CPWM) for neutral-point-clamped three-level inverters (NPC-3LI) with a previa boost converter. The modulation voltages of space vector PWM (SVPWM), discontinuous PWM 1(DPWM1), and 240CPWM are obtained based on carrier-based PWM. The losses of IGBTs and SiC MOSFETs are mainly analyzed. By analyzing the characteristics of the switching devices and the phase relation between the modulation voltage and output current, the conduction loss and switching loss of each switching device in NPC-3LI can be determined. Comparing the loss distribution of the NPC-3LI with three PWM strategies applied, it is concluded that the device has the lowest loss when using 240CPWM. The switching losses of the bridge arm IGBTs in each phase can be reduced by 88% compared to SVPWM at unit power factor. When using 240CPWM, the loss distribution of NPC-3LI is more uniform.