A simple method for balancing the DC-link voltage of three-level inverters

Abstract

In this paper, a simple control method for balancing the DC-link voltage of three-level neutral-point-clamped (NPC) inverters is presented. The method is based on DC-DC power converter technology. In addition, the proposed topology is enhanced to also improve the NPC inverter's ride-through ability. Simulation results are supplied to confirm the validity of the proposed method for conventional sinusoidal pulse width modulation (SPWM) schemes and common-mode voltage cancellation.