A Highly Efficient Multifunctional Power Electronic Interface for PEV Hybrid Energy Management Systems

Abstract

In the hybrid energy management systems of plug-in electric vehicles (PEVs), a power electronic interface (PEI) is required to connect the grid side dc link, the ultracapacitor bank, and the battery pack. To realize this PEI, the conventional method is deploying multiple independent dc/dc converters and it suffers from bulky size and high hardware cost. In this paper, an integrated multifunctional PEI is proposed to effectively mitigate those issues. The proposed PEI enables three functions—grid to vehicle (G2V), vehicle to grid (V2G), and PEV driving. It integrates the CLLC resonant topology with the bidirectional interleaved buck/boost topology, in which the former is utilized in the G2V and V2G modes, while the latter is in charge of the driving mode. Due to circuit reuse of the secondary side full-bridge structure, the system components count is reduced effectively. A synchronous rectification (SR) technique is developed to actively control the MOSFETs in CLLC rectification stage. Soft switching and SR techniques work in synergy to ensure a high conversion efficiency. An experimental prototype is designed, optimized, and tested for all three working modes. A peak efficiency of 98.27% for the G2V mode, 98.04% for The V2G mode, 98.56% for the PEV driving mode and good overall efficiency performances are reported.