Conditions for maximum energy transfer in inductive road-powered electric vehicle applications taking system limitations into account

Abstract

This paper deals with the problem of maximizing the energy transfer between infrastructure for inductive power transfer embedded in the road and a moving electric vehicle. The analysis is assuming a series-series compensated inductive power transfer architecture and the problem is solved analytically to obtain general solutions expressed in terms of basic coil parameters and coupling. Based on the analytical solutions, control algorithms aiming at maximum energy transfer during the vehicle motion are developed, resulting in optimal utilization of the infrastructure. Numerical simulations and experimental measurements are used to validate the proposed method. It is shown that by using power transfer maximization control, the amount of energy transferred from the road infrastructure to a moving vehicle can be significantly increased compared to using conventional techniques. In this paper, about 10% higher energy could be transferred without changing the current and voltage ratings of the coils and converters. Higher gain is expected for different system designs with road and on-board coils more similar in size. Copyright © 2021 Society of Automotive Engineers of Japan, Inc.