A Self-Compensated Planar Coil With Integrated Single-Switch Regulator for Wireless Power Transfer (WPT) Systems

In the receiver-side (R _X ) of the wireless power transfer (WPT) system, the R _X is composed of compensation capacitors, a rectifier stage, and a dc/dc stage. Among them, the compensation capacitors are an essential component to minimize reactive power. Also, the dc/dc stage is an inevitable component to supply a stable output to the battery. However, to meet these aforementioned unavoidable requirements, a large number of components are required in R _X of the WPT system, which increases the overall system size and cost. To relieve these drawbacks, a self-compensated planar coil with integrated single-switch regulator for the WPT system is proposed in this letter. The proposed converter can remove the many number of compensation capacitors by utilizing the intrinsic capacitance between adjacent layers of the planar coil as a self-compensated factor. Moreover, by integrating a single-switch into the rectifier stage, it is possible to supply a stable output to the battery with only a single power stage and low cost. Besides, the proposed structure can obtain reduced switching loss by securing the soft-switching operation under the rated load condition. The effectiveness of the proposed structure is verified experimentally by a prototype under 150 V_DC input and 60 W/33 V output.