A novel switching sequence design for five-level NPC/H-bridge inverters with improved output voltage spectrum and minimized device switching frequency

This paper presents a novel flexible 3-seqment switching sequence for the space vector modulation (SVM) of high-power multilevel converters. The switching sequence is optimized for the improvement of harmonic spectrum and the minimization of device switching frequency. Compared to other commonly used switching sequences, the output voltage spectrum of the proposed scheme shows higher inverter equivalent switching frequencies and lower device switching frequencies. The proposed switching sequence is simulated and experimentally tested on a 5-level neutral point clamped (NPC) H-bridge based inverter. Both simulation and experimental results verify the above-mentioned features.