Scale Reduction for Modeling and Prototyping of Inductive Power Transfer System for EV Applications

In this article, the scale reduction method is applied to an induction power transfer system for electric vehicle (EV) charging for its rapid and low-cost prototyping. In addition, a co-simulation method is proposed, which is based on the coupling between a circuit analysis and a finite-element (FE) analysis. Then, it is proposed to combine the scale reduction method with the co-simulation method to consider, at the same time, the nonlinearities due to the power electronic converter and the magnetic material characteristics of the system. Finally, a 1 kW experimental IPT system is proposed to validate both methods.

I. Introduction

The massive development of electric vehicles (EVs) is a major ecological imperative to replace conventional vehicles that use combustion engines. These vehicles use batteries instead of fossil fuel onboard to store the electrical energy needed to propel the vehicle. Large capacity, high-power battery packs are generally required for EVs to operate over reasonable distances. However, it is not easy to realize reliable and competitive batteries for EVs in 1–10 kW range due to the requirements of cost, safety level, power densities, long cycle life, volume, and weight, which should all be satisfied simultaneously. Currently marketed lithium-ion batteries for EVs are recognized as the most competitive solution, but the power densities of lithium-ion batteries are less than 100 Wh/kg [1], [2]. On the other hand, gasoline has an energy density of about 12000 Wh/kg [3], which implies that EVs are not sufficiently attractive compared with conventional vehicles to date.