Development of digital experiment system for multi-module-cascaded multilevel high-power inverter

Based on a multi-module-cascaded multilevel inverter structure for the optimization of harmonics, this paper introduces a horizontal phase-shifting sinusoidal pulse width modulation (SPWM) strategy applied to multi-module-cascaded inverter, and at the same time, based on digital signal processor (DSP) and complex programmable logic device (CPLD), this paper also presents a digital algorithm for horizontal phase-shifting SPWM modulation, which has solved the problem of the exactly lock of each triangular carrier phase in the multi-module-cascaded system. The simulation and experimental results have proven the method proposed correct.