Fully-Actuated Control for The Balance of Neutral Point in Three-Phase Four-Leg DC/AC Converters

Neutral-point clamped (NPC) three-level inverter is widely used in medium and high power circuits because of its low harmonic content and good voltage withstand capability of switching tubes, but it is necessary to carry out the mid-point voltage balancing control of NPC three-level inverter in the practical application; in this paper, on the basis of NPC three-level inverter with increased bridge arms, the paper proposed a fully-actuated control method, the mathematical model is established and the control rate is deduced. The simulation results verify the neutral point voltage balance effect of NPC three-level inverter.