Energy-Efficient Optimization of Magnetized Pavement Structures for Interoperability of Inductive Power Transfer Magnetic Couplers in Electric Vehicles

Abstract

Integrating inductive power transfer (IPT) systems into pavements addresses the inconvenience of charging electric vehicles (EVs) and promotes renewable energy use. Magnetized pavements are likely to be desirable in future. However, the factor of magnetized pavements has not been considered in interoperability studies. This paper investigated the interoperability of four types of coupling coils commonly used in IPT systems, circular (C), rectangular (R), double D (DD), bipolar (BP). Inductive coupling coefficient and IPT system tests was conducted to compare coil coupling under air and magnetized pavements, examining effects of transmission and offset distance on coil coupling and system performance. The results showed magnetized pavement enhanced the coupling performance of C-C, C-R, C-DD, C-BP, R-C, R-R, and R-BP couplers, while weakening others. The couplers can be divided into three categories: Type Ⅰ (C-C, C-R, R-C, R-R) with highest coupling coefficients, Type Ⅱ couplers reaching coupling zero at 100-120 mm offset, and Type Ⅲ couplers reaching zero when aligned, requiring transverse offset for energy transfer. Efficiency should be the primary evaluation index for reducing energy loss. The R-R coil had the highest transmission efficiency (69.6%). For wireless charging technology, R-R type couplers are recommended to promote EV development and renewable energy utilization.

Keywords: electric vehicles, inductive power transfer, magnetic couplers, interoperability, magnetized pavement