A discontinuous PWM for three level converters with constant common-mode voltage

This study proposes a three level neutral-point-clamped (NPC) converter operated with constant common-mode voltage (CMV) pulse width modulator (PWM). The CMV and common-mode current (CMC) of the NPC converter are reduced by the constant CMV PWM scheme. Furthermore, the discontinuous PWM scheme is utilized to reduce the switching losses of the three level NPC converters. Simulation results and test results are presented to validate the performances of the proposed scheme.