Theoretical Analysis of Litz-Wire DD Coil for Wireless Power Transfer System

Coupler design becomes a key factor affecting efficiency and practicality in the rapidly evolving field of wireless power transfer systems, especially in the field of electric vehicle charging. The design of different coupler systems will have different self-inductance, mutual inductance and AC resistance, which will affect the energy transmission efficiency and transmission capacity of the system. However, the coupler design purely relying on finite element analysis (FEA) software is time-consuming. In this paper, the inductance of the DD planar coil is calculated using the theoretical calculation method, and the wire spacing and number of turns at different positions of the DD coil are changed respectively when other coil parameters are unchanged, and the inductance of the DD coil under different parameters is calculated and the simulation under different parameters is performed to obtain the simulation value of the DD coil inductance. By comparing the calculated inductance value of DD coil with the simulation value, the accuracy of the theoretical calculation method of DD coil inductance in this paper is obtained, and certain guidance is provided for the design and simulation of DD coil, avoiding the workload caused by the repeated design of coil model caused by the cumbersome change of simulation model parameters.