Research on the Coordination Suppression Strategy of Neutral Point Potential and Common Mode Voltage for NPC Three-Level Inverter

A Neutral Point Clamped (NPC) type three-level inverter has the advantages of a low switch voltage and high-quality output waveform. However, there are inherent problems, such as neutral point potential asymmetry common mode interferences, which easily affect symmetry three-phase safe operation inverter. Firstly, according to different modulation degrees, fluctuation midpoint can be suppressed by adding an action time correction factor traditional space vector pulse-width (SVPWM) strategy virtual (VSVPWM) strategy, respectively. Secondly, considering suppression voltage, new (NVSVPWM) is proposed, uses set synthesis methods. Finally, simulation experiment prove that NVSVPWM with suppress at same time, effect significant.