Efficient Methodology of the Coil Design for a Dynamic Wireless Charger

Abstract

Dynamic charging is a promising technology that will increase the use of electric vehicles with reduced battery requirements. Designing this type of system is more complex than for a static charger, and leads to a significantly higher demand of computational resources. First, the complex geometries of the coils do not allow analytical equations to be used, and FE tools must therefore be used instead. However, the Litz wire conductor used in these coils will pose a computational problem if it is not well modelled. The second difficulty is that these systems should be analysed with more potential relative positions between the coils, as misalignment is intrinsic in a dynamic charger. These two complications mean that the design process can greatly benefit from techniques that reduce the time taken to derive the coil parameters. This paper shows the feasibility of using an equivalent layer to model the Litz wire in a dynamic charging application, which significantly reduces the computational time of each iteration up to 20 times. As a consequence, the complete design process is faster and accurate. For this demonstration, we illustrate the design for a dynamic charger of a remote control car.

Keywords

• Coil design
• electric vehicle
• dynamic charge
• wireless power transfer
• Litz wire modelling