New Single-Stage Single-Phase Isolated Bidirectional AC-DC PFC Converter

Abstract

This article presents a novel single-stage, single-phase isolated bidirectional AC-DC converter for grid-connected applications. It utilizes a unique anti-series half-bridge structure on the AC side where the switch’s anti-parallel diodes elevate the AC side capacitor voltages to DC voltages without the necessity of active control. This design obviates the need for an AC switch bridge or an additional full-bridge unfolding bridge commonly found in other approaches. The modulation strategies employed on both the AC and DC sides are detailed. A Dual Active Bridge (DAB) type of operating scheme is employed to achieve a wide Zero Voltage Switching (ZVS) range. An analysis of the ZVS operating range and switching stress is performed using a Fast-Fourier-Transform (FFT)-based modeling approach.