A Switched-Capacitor-Based Five-Level ANPC DC–AC Power Converter With Full DC-Bus Utilization

Abstract

This paper presents a self-balanced five-level active neutral-point-clamped inverter with unity voltage gain. The proposed topology consists of seven active switches, six diodes, a low-voltage switched capacitor, and two dc-link capacitors to generate a five-level output voltage without requiring an additional voltage-boosting stage. The switched capacitor is naturally charged and discharged during operation, enabling automatic voltage balancing without auxiliary sensors or balancing circuits. In addition, the inverter achieves reduced capacitor voltage ripple, lower switched-capacitor energy processing, and low semiconductor voltage stress while maintaining a simple structure with a reduced component count. The operating principle, modulation strategy, and component stress characteristics are analyzed in detail. The feasibility of the proposed topology is verified through simulation and experimental studies on a 400-W laboratory prototype. The results demonstrate stable capacitor-voltage balancing, high-quality five-level output-voltage generation, and a peak efficiency of 97%, confirming the effectiveness of the proposed inverter topology.