A Hybrid Five-Level Single-Phase Rectifier with Low Common-Mode Voltage

Abstract: Rectifiers with high efficiency and high power density are crucial to the stable and efficient power supply of 5G communication base stations, which deserves in-depth investigation. In general, there are two key problems to be addressed: supporting both alternating current (AC) and direct current (DC) input, and minimizing the common-mode voltage as well as leakage current for safety reasons. In this paper, a hybrid five-level single-phase rectifier is proposed. A five-level topology is adopted in the upper arm, and a half-bridge diode topology is adopted in the lower arm. A dual closed-loop control strategy and a flying capacitor voltage regulation method are designed accordingly, so that the compatibility of both AC and DC input is realized with low common voltage and small passive devices. Simulation and experimental results demonstrate the effectiveness and performance of the proposed rectifier.

Keywords: multilevel rectifier; 5L-ANPC; low common-mode voltage; AC-DC hybrid input