An Integrated Electric Vehicle Charging System of Wireless Power Transfer and Auxiliary Power Module With Shared Converter and Magnetic Coupler

Abstract

Electric vehicles (EVs) normally contain two kinds of batteries: high-voltage (HV) power battery and low-voltage (LV) auxiliary battery. The charging systems for these two kinds of batteries are normally independent and separate. This article proposes an integrated charging system that combines wireless power transfer (WPT) for the HV battery and the auxiliary power module (APM) for the LV battery. Part of the power electronics converters and compensation network is shared. The doubled-sided <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LCC</i> topology is adopted with a constant-current output. An APM transformer is inserted in the constant-current branch to pick up power for the LV and also to guarantee the independent HV and LV outputs. The proposed system can work in two modes. One is WPT and APM where both the HV and LV batteries can be charged simultaneously. The other is APM where the HV battery supplies power for the LV battery. The integration of WPT and APM can improve the overall power density of the EV charging system and reduce the weight and cost.