Optimal Simulation Study for Wireless Charging Coils with Magnetizers

Abstract

In order to increase the mutual inductance between wireless charging coils of electric vehicles (EVs) and to improve the charging efficiency, the effect of magnetizer is analyzed by using the circuit theory. Based on planar spiral coils, three types of magnetizer structures, i.e. the disc types (including two structures) and the lampshade type, are designed in this paper. Moreover, four types of coils, one without magnetizers and three with three types of magnetizers, are simulated and compared using COMSOL. The magnetic flux density distribution diagrams of four types of coils and corresponding system transfer efficiencies are obtained. The simulation results show that: 1) magnetizers can help increase the magnetic flux passing through both transmitting and receiving coils and improve the wireless charging efficiency of EVs; 2) the length of magnetic circuit occupied by magnetizer should be increased as much as possible in the magnetizer structure design.