A multilevel inverter approach providing DC-link balancing, ride-through enhancement, and common-mode voltage elimination

Abstract

This paper presents a simple control method for balancing the DC-link voltage of three-level neutral-point-clamped inverters, while providing enhanced ride-through and common-mode voltage (CMV) elimination. The method uses DC-DC power converter technology on the DC link for balancing and ride-through enhancement, and a modified pulsewidth-modulation switching algorithm for CMV elimination. Simulation and experimental results are supplied to confirm the validity of the proposed method, which includes full digital signal processor control.