Design of Compact Three-phase Receiver for Meander-type Dynamic Wireless Power Transfer System

Three-phase meander-type dynamic wireless power transfer is ideal for the power supply or charging of rail vehicles. However, there is a lack of systematic analysis and design of the three-phase receiver. To achieve the compact design of the three-phase receiver in practical applications, this article studies the compact three-phase receiver with overlapped receiving coils and ferrite core. Based on the analysis of the fundamental coupling characteristic of three-phase meander-type dynamic wireless power transfer, two overlap modes of the receiving coils are concluded and compared. Meanwhile, by considering the influence of mutual inductance harmonic distortion, the accuracy of the receiving coil analysis and design is improved. Furthermore, a practical distributed strip core design is presented to enhance the coupling between transmitting coils and receiving coils. Additionally, the effect of the core on coupling imbalance is analyzed in detail and proves to have little effect on the power transfer. Afterward, a design flow of star-connected series-compensated receiver with the overlapped coils and the distributed strip core is proposed. Finally, for verification, a small prototype with an average output power of 154 W and average efficiency of 97% of the receiving coils is established.