Optimisation of planar rectangular coil achieving uniform magnetic field distribution for EV wireless charging based on genetic algorithm

Abstract

Inductive power transfer is a method that can be used to transfer power to electric vehicles. The output power and the transmission efficiency drop significantly when there is a misalignment between receiver on the vehicle and transmitter on the parking spot. This can be resolved by designing the transmitter coil that produces uniform magnetic fields for wireless charging. Here, a planar rectangular coil with unevenly spaced turns is proposed for improving the uniform magnetic field distribution over the charging zone, together with the genetic algorithm for determining the geometric parameters of the coil structure. An analysis that is divided into four design variables is presented. The magnetic characteristic of the optimal unevenly spaced transmitter coil using genetic algorithm and optimal evenly spaced transmitter coil using conventional method are compared and analysed. The uniform magnetic field distribution of the designed prototype is measured by an electric and magnetic field probe and by a receiver coil. The measured results agree well with the theoretical values and validate the improved uniform magnetic field distribution.