A Single-Stage Three-Phase Bidirectional AC/DC Converter With High-Frequency Isolation and PFC

This paper presents a novel single-stage ac/dc rectifier with high-frequency isolation and bidirectional power flow capability, which is feasible to connect dc grids to ac ones. A thorough analysis is performed based on the development of an actual model as well as a fundamental one using the double-sideband amplitude modulation equations. The derived models allow the determination of the active and reactive power flow through the transformer as well as defining the operating regions for which soft commutation is achieved. Besides, the current stresses of the semiconductors devices are analyzed in detail. Experimental results obtained from a 5 kW prototype are presented and discussed in order to validate the proposed model as well as demonstrate the converter's performance and claimed advantages. The proposed concept can also be extended to dc/dc, ac/ac, and multilevel topologies.