Fast and fault‐tolerant model predictive control of MMCs under selective harmonic elimination

Selective harmonic elimination (SHE) is a suitable pulse-width modulation (PWM) technique for some applications of modular multilevel converters (MMC) with lower number semiconductor submodules (SM). However, SHE can make it difficult to control circulating currents in the MMC. Moreover, MMC vulnerable SM switch failures that reduce its output power magnitude and quality. This paper proposes fault-tolerant model predictive strategy MMCs operating (FT SHE-MPC). The effects failure on phase voltage waveforms are studied first. Then, method proposed design FT waveform preserve performance. Next, SHE-MPC designed increase capacitor voltages during an maintain fundamental component faulty currents, maintaining balance among line Additionally, offers as much 60% faster transition time 36% ripple. advantages verified through offline real-time simulation studies three-phase nine-level PSCAD/EMTDC software RTDS.