Comparison of Phase-Shift and Step Wave Modulation Technique applied to Symmetrical Cascaded Multilevel Inverter

This paper presents a comparison between the phase-shift and the step wave modulation techniques applied to symmetrical cascaded multilevel inverter. Initially, the phase-shift modulation and a simple method to determine the switching angles used to generate a step pulse waveform are presented. Performance indices as harmonic spectrum, total harmonic distortion, common mode voltage, power losses in semiconductors devices and first/second distortion factors are analyzed to demonstrate the performance of these modulation techniques. The modulation strategy that presents more advantages is implemented in FPGA and the experimental results are presented.