The development of multi-module-cascade high-power inverter

Based on the conventional sinusoidal pulse width modulation technique (SPWM) and the multi-module-cascade circuit topology configuration, this paper proposes an optimized pulse width modulation (PWM) technology, which combines the dual sinusoidal pulse width modulation (DSPWM) technique applied to each inverter module and the phase-shifting sinusoidal pulse width modulation (PS-SPWM) technique. This modulation obtains high equivalent carrier frequency through canceling the lower harmonics, hence the device loss is decreased significantly; at the same time, owing to the special topology, the range of the output voltage is extended, and the high power capacity of the inverter system is realized. At last, a 30 kW high-power inverter is developed.