Fault Analysis and Clearance in FL-APC DC–AC Converter

Abstract

The traditional active neutral-point-clamped (APC) dc–ac converter maintains great common-mode voltage with high-frequency (CMV-HF) reduction capability, so it has limited voltage gain. This article presents a new five-level APC (FL-APC) dc–ac converter capable of voltage step-up in a single-stage inversion. In the suggested design, a common ground not only reduces the CMV-HF but also improves dc-link voltage usage. While comparing with traditional two-stage FL-APC dc–ac converter, the proposed design has lower voltage stresses and greater uniformity. While improving overall efficiency, the suggested clamped dc–ac converter saves three power switches and a capacitor. Modeling and actual tests have proven the suggested APC inverter’s overall operation, efficacy, and achievability. The proposed circuit is finally tested with fault clearance capability.