A design algorithm of circular transmitting coil to achieve uniform magnetic field distribution in WPT applications

Circular planar coil is one of the most popular structures in wireless charger for electric vehicles and portable devices. A methodology of transmitting coil design to achieve the uniform distribution of axial magnetic field strength on the charging plane where the receiving coils placed was proposed. The coil structure design was regarded as a parametric optimization problem and solved by Adaptive Genetic Algorithm (AGA). Some design examples were performed and simulated by Finite Element Method (FEM). A transmitting coil of 15 turns was made and the field was measured to verify the design results. The multi receiving coils were also made to test the feature of constant mutual inductance.