Research on cross-decoupling of multirelay magnetic coupling wireless power transfer system

In order to solve the cross-coupling problem in the multirelay magnetic coupling wireless power transfer (MC-WPT) system, a set of magnetic cross-decoupling coil structure is designed in this paper. The coupling mechanism uses the mutual decoupling principle of bipolar coils and unipolar coils to realize the decoupling of non-adjacent coils, while the adjacent coils remain coupled. The frequency characteristics and output characteristics of the cross-decoupling dual-relay system based on the LCC-Multi-S topology are studied. It is found that the system can achieve open-loop constant voltage (CV) output, and the frequency of the optimal efficiency does not deviate from the resonance frequency point. At the same time, the proposed coil structure is compared with the traditional four-coil structure. The experimental results show that the proposed coil structure achieves cross-decoupling and better CV output, suppresses frequency drift and improves system stability.