Research on Key Influence Factors of Independent Double Three-Phase Common-Bus Five-Level NPC/H Bridge Inverter DC-Link Capacitor Voltage Fluctuation

This paper aims at the DC-link capacitor voltage fluctuation problem of independent double three-phase common bus five-level NPC/H bridge inverter. Firstly, the topological structure of the research object is described. Secondly, the principle of voltage balance control of the inverter is described, and the objective function characterizing the DC-link capacitor voltage fluctuation is derived, to get the relation between the key factors and the voltage fluctuation. Finally, on the semi-physical real-time simulation platform, the influence laws of each key factor on the capacitor voltage fluctuation are analyzed and summarized, and some suggestions and research directions for the method of voltage balance control are put forward.