DC-Link Neutral Point Control for 3L-NPC Converters Utilizing Selective Harmonic Elimination–PWM

Selective harmonic elimination–pulsewidth modulation (SHE–PWM) is a technique widely used to improve the efficiency and content in medium-voltage high-power converters. Among these converters, three-level neutral-point-clamped (3L-NPC) converter one of most utilized topologies. However, 3L-NPC requires proper balancing dc-link capacitor voltages. This article presents control technique, based on pulse shifting method, regulate neutral point voltage when SHE-PWM utilized. The proposed performs well with any power factor it can also be directly applied T-type converters easily extrapolated other multilevel method experimentally validated scaled-down full-scale converter.