Assessing the Impact of Pavement Material as Transmission Medium on the Interoperability of Magnetic Couplers for Inductive Electric Vehicle Charging

Integrating inductive power transfer (IPT) systems into pavements provides a viable solution to the challenges of charging electric vehicles (EVs), thereby facilitating an increase in electric vehicle ownership and advancing the electrification of transportation. Pavement material is an important factor in the application of IPT system. This paper investigated the interoperability of four magnetic couplers commonly used in IPT system, including rectangular-circular (R-C), rectangular-rectangular (R-R), rectangular-double D (R-DD) and rectangular-bipolar (R-BP), with the presence of pavement material. Through induction coupling coefficient and IPT system performance tests, we evaluated the impact of air and pavement material mediums on coupling efficiency, as well as the effects of transmission and offset distances on system performance. The results indicate that pavement material enhanced the coupling performance of R-C, R-R, and R-BP couplers but degraded that of R-DD couplers. The R-R and R-C couplers exhibited notably higher coupling coefficients compared to the R-DD and R-BP couplers, with the latter demonstrating superior resistance to migration. The IPT system, using R-R couplers, achieved the highest output power and transmission efficiency (224.9W and 82%, respectively). The overall performance ranking identified the R-R coupler as the most effective, followed by the R-C, while the R-BP scored the lowest. This study underscores the superior interoperability and performance of rectangular couplers in IPT systems, recommending their use to boost the electric vehicle industry and enhance renewable energy utilization.