Selective harmonic elimination pulse‐width modulation of modular multilevel converters

Abstract

The modular multilevel converter (MMC) is the state‐of‐the‐art for multilevel converter topologies. This study presents the operation of the MMC using the multilevel selective harmonic elimination pulse‐width modulation (MSHE‐PWM) technique. MSHE‐PWM offers tight control of the low‐order harmonics and the lowest switching frequency for the power semiconductors among all modulation techniques. A comprehensive analysis of the modulation methods for the MMC leads to two different modulation patterns for MSHE‐PWM. A method for selecting the number of sub‐modules in the phase‐legs of the converter is also proposed in this study. Simulation results for both patterns are provided and verified through matching experimental results from a single phase 11‐level laboratory prototype.