Decoupling design of multi-coil wireless power transfer system with metal insulator

Comparably multi-coil wireless power transfer (WPT) system can achieve higher transmission efficiency or larger transmission distance. However, due to complicate magnetic coupling relationships between the coils it is difficult to analyze and design these system. Regarding to this problem, a metal-insulator based magnetic decoupling method is proposed in this paper, so that the complicated multi-coil WPT system can be decoupled into several independent two-coil sub-systems. In this way, the output characteristics for each subsystem can be designed independently, and passive compensated network is applied to guaranteeing constant-voltage output. The transmission efficiency and the constant-voltage effectiveness for a four-coil WPT system are analyzed in theory, and some simulation and experimental results are given as well.