Analysis of a Load-Independent and Novel Design Double-Sided LCC Hybrid Compensation Topology for Wireless Power Transfer System

Wireless power transfer (WPT) has been recently preferred to be used in many devices such as household electronics, electric vehicles and biomedical tools due to its high reliability and advantages. Constant current (CC) and constant voltage (CV) charging applications are required for Li-ion batteries to enhance efficient charging and its lifetime. However, it is difficult task to perform CC and CV charging due to the change of the battery load, which ranges from a few to several hundred ohms. Additionally, a zero phase angle (ZPA) is necessary over the whole charging operation to improve power transfer performance and efficiency. This study proposes a novel double-sided LCC topology to perform load-independent CC and CV charging modes at a single resonant frequency. Also, it ensures ZPA at the resonant frequency without the use of any additional power converter or control technique. In the proposed circuit, the CC and CV modes are selected via placed two additional AC switches (ACs) and inductors on both primary and secondary sides of the circuit. The proposed topology eliminates the need of variable frequency control or tuning of the coupling coefficient for CC and CV modes. Hence, this makes the proposed circuit simplified control and provides stable output. In this study, a 7.9 kW prototype was realized in simulation to verify the proposed topology.