Parasitic Capacitance Analysis in High-Frequency Wireless Power Transfer Systems

Megahertz-range wireless power transfer (WPT) system through inductive coupling has become increasingly popular during the past years. As a critical part of high-frequency WPT, parasitic components of the coils must be carefully considered because of their great impacts on the system's operation. In this paper, we propose an analytical method to deal with this problem by adding compensation capacitors on each side of the coils and calculating the appropriate value of these capacitors to attain the maximum load power and efficiency. This work is performed on the 6.78-MHz WPT system to illustrate the characteristics and enhance the robustness of the system.