Reconfigurable topology of electric vehicle wireless power transfer system to achieve constant-current and constant-voltage charging based on multiple windings

Abstract

In the wireless charging system of electric vehicles, different charging stages have different charging requirements, namely constant-current (CC) charging mode and constant-voltage (CV) charging mode. The purpose of this paper is to provide a multi-winding wireless charging system with a reconfigurable topology to realize CC and CV charging with different optimal load resistances so that high efficiency can be achieved over a large load resistance range. The designed system can form different compensation topologies by switching on and off relays, such as the series–series topology and the inductor–capacitor–capacitor-series topology. Different topologies have different optimal load resistances, therefore, it can realize efficient transmission in a large load resistance range. In addition, the half-bridge scheme and the full-bridge scheme are the other two functioning modes for each topology. At the same time, the efficiency of the system can reach up to 94.34% and 95.13% in the half-bridge as well as full-bridge schemes under the CC mode. The highest transmission efficiency can reach 93.37% and 90.78% for the half-bridge as well as full-bridge schemes under the CC mode, respectively. Experiment results have validated the proposed method.