INVESTIGATION OF MAGNETIC PROPERTIES FOR DIFFERENT COIL SIZES OF DYNAMIC WIRELESS CHARGING PADS FOR ELECTRIC VEHICLES (EV)

Abstract

Electric Vehicle (EV) has been introduced in the recent years due to public awareness of effect of gas emission from traditional car and the extinction of petroleum natural resources. For the charging of EV, dynamic wireless charging is considered in this paper. This is because it is more convenient and saves the charging time since it charges the electric vehicle while moving. The main challenge of this process is to maintain high amount of power transfer from primary to secondary coil. One of the factors to have a good power transfer is the size of the coil. There are various designs of coil for wireless charging of electrical vehicle (EV). Among the most common design are circular pad (CP), rectangular pad (RP), double-D pad (DDP) and double-D quadrature pad (DDQP). In this paper, circular pad (CP) is chosen to be used due to its simplicity in design and it has a good electrical and magnetic properties. Three different coil pair sizes are tested to find the most suitable coil pair for primary and secondary pad which has the maximum power transfer and least sensitive to misalignment. The magnetic properties have been investigated to obtain the highest value of magnetic flux. The geometry design of the pads and simulation was done using COMSOL Multiphysics software. From the simulation, it was found that the unsymmetrical coil pair gives high magnetic strength when the outer diameter for primary and secondary coil has the same value.