An Intermediate Coil for Misalignment Tolerant IPT System with Dual Decoupled Receivers

Misalignment between the magnetic coupled coils of inductive power transfer (IPT) system is inevitable, which significantly reduces the power transfer capability and system efficiency of IPT system. In this paper, an intermediate coil and dual decoupled receivers are employed to achieve high misalignment tolerance of IPT system. Besides, constant current (CC) output characteristic is obtained. Thanks to the intermediate coil, the inverter current can be limited when the receiver side moves out of the operating region (the mutual inductances are close to zero). With the proposed decoupled method, the design of the magnetic coupler is significantly simplified. In order to demonstrate the validity of the proposed method, a 3.2kW experimental prototype is designed and implemented. Experimental results show that the proposed IPT system can tolerate ±210mm x-axis and -20mm~60mm z-axis misalignment while the fluctuation of the output current is within ±5%. The maximum efficiency can reach 96.7% at full load.