An Effective Integration of APM and OBC With Simultaneous Operation and Entire ZVS Range for Electric Vehicle

This article proposes an effective integration of APM and OBC providing simultaneous operation without an extra circuit and entire ZVS range of all switches. The integrated circuit of the proposed charger is configured by combining high voltage-side switch legs of the LLC resonant converter of OBC and the PSFB converter of APM. In the simultaneous mode, by operating the common leg as a lagging leg of the phase-shift full bridge (PSFB) converter, the conduction losses of the common leg switches are decreased due to current cancellation effect, and the lagging leg switches of the PSFB converter achieve entire ZVS operation. Further, in the APM standalone mode, entire ZVS operation of the lagging leg switches is also secured by utilizing the magnetizing current of the LLC resonant converter. As a result, the proposed integrated charger achieves comprehensive improvement in terms of efficiency as well as volume and cost. A laboratory prototype combining a 3.7-kW LLC resonant converter with a 1-kW PSFB converter is built and tested in order to verify the performance and theoretical claims.