Power Quality Optimization of Post-Fault Reconfigured Multi-Level Inverter

This paper investigates the effect of impact factors (IFs) to harmonic content of an electric machine drive circuit, post-fault reconfigured multilevel inverters (MLIs) by using an accurate mathematical model, and impact of reconfiguration methods on THD. Due to the difficulty of analyzing harmonic content of MLIs mathematically, software tools are typically used to simply calculate the value of THD as metric. In this paper, an accurate mathematical model including both low- and high-frequency contents of harmonics in MLIs is utilized to derive the general expression of their output voltage THD. The effect of IFs on harmonic content are analyzed based on the general expression. Simulations and experiments are performed to validate the proposed mathematical model. The impacts of the reconfiguration methods on THD are analyzed. The impact of THD and other essential metrics on power quality are analyzed, and an minimal degradation of power quality caused by reconfiguration methods is proposed.