Transfer characteristics analysis of bilayer coil structures for wireless power transfer systems

Although bilayer coil structures can satisfy the application requirements for inductively coupled power transfer (ICPT) systems in practice, the transfer characteristics of systems (e.g., transfer power, transfer efficiency, and misalignment tolerance) under external interference are seldom studied. In this paper, an equivalent model of a wireless power transfer (WPT) system with a bilayer coils structure was established, and the influences of coil structures on transfer power and efficiency were analyzed. Then, the bilayer coil structures were modeled through multi-physics simulations, the applicable range was determined, and the influences of the coil structures on the transfer performance were studied in detail. Finally, an experiment prototype was set up, and experimental results showed that the coupling coil structures has an obvious effect on the transfer performance. The research in this paper is beneficial for the operation safety and reliability of WPT systems.