Analysis and comparison of power losses in 3L-NPC inverter with SHPWM control

The power losses of switch device are disadvantages that restrict the performance of a converter. Sub-harmonics PWM (SHPWM) is applied in modulation of three-level neural-point-clamped (3L-NPC) converter most widely. This paper analyzes and compares the conduction losses and switching losses for 3L-NPC converter for different SHPWM strategies (PDSPWM, PDTHIPWM, PDSVPWM and PDSLRPWM). The principle of PDSLRPWM is also described in this paper. Some interesting conclusions can be come to according to the simulation and analysis results.