An Enhanced Space Vector PWM Technique for Neutral Point Balancing in Three-Level NPC Inverter

Neutral point clamped inverter is best-suited topology for medium-voltage applications. But NPC inverters have problem of neutral unbalancing due to various factors. This neutral voltage can be balanced by modifying the gating signals to the switches. This paper presents enhanced space vector modulation (SVM) for balancing the neutral voltage. In the proposed method, according to unbalance conditions, small switching states are replaced by other states that regain the balanced condition.