This paper introduces 240-degree clamped pulse-width modulation strategy (240CPWM), traditional space vector modulation (SVPWM) and discontinuous pulse width modulation (DPWM1) for neutral-point-clamped three-level (NPC-3LI) inverters with a previa boost converter and provides a reasoned analysis of the capacitive ripple current with three PWM strategies and derives the calculation expressions. Using 240CPWM in inverters can greatly reduce switching losses, especially at a power factor of 1, which reduces switching losses by 85% and has nearly equal total harmonic distortion (THD) compared to SVPWM. In comparison, using 240-degree clamped pulse width modulation strategy can reduce the value of capacitive ripple current at full power factor, especially at high power factor, which will help reduce the volume on the DC side support capacitor.

neutral-point-clamped;PWM;three-level inverters;ripple