A Novel Single-Stage Bidirectional Isolated Three-Phase Resonant Mode AC-DC PFC Converter

This article presents a novel single-stage three-phase series-resonant dual-active-bridge (DAB) type AC-DC converter for grid-connected bidirectional application. The Y-configuration is employed on the AC side where the input capacitors and switch anti-parallel diodes can automatically lift up the AC side voltages into DC without active control. Eliminating a forehead unfolding bridge or an active rectifier stage, this topology decreases the switch count compared to existing topologies. The number of Magnetic components is also reduced by using a three-phase three-limb high-frequency transformer (TPTL-HFT). An equivalent circuit with the TPTL-HFT is derived and analyzed. A novel Fast-Fourier-Transform (FFT) based modeling method is employed to analyze the system's ZVS range, switching currents, conduction currents, and thus semiconductor losses. Simulation in PLECS is implemented to verify the model results. The total efficiency is expected to be 98.8%.

I. Introduction

In the future energy system, the bidirectional AC-DC power electronic conversion system with galvanic isolation will be widely used.