Resonantly Coupled Wireless Power Transfer for Non-Stationary Loads With Application in Automotive Environments

Abstract

Resonantly coupled wireless power transfer (RWPT) has become a popular means to deliver energy without direct contact between the source and load. One challenging application is nonstationary loads; those that move spatially in time. Such loads change the coupling between the source and load and with it the efficiency and maximum power transfer possible. One emerging application is in the automotive environment, where nonstationary loads such as powered seats and doors exist. Moreover, the automotive environment is particularly challenging due to the presence of metallic objects and the safety requirements of the passengers. In this work, we examine RWPT for nonstationary loads and present a design methodology for optimal efficiency and power transfer and show an RWPT of 70 W across a 24 cm distance in an automotive environment. We also examine the impact of the metallic environment and show how its effects can be mitigated. Finally, we examine the field intensity during RWPT and examine the safety of the passengers. We show that 70 W can be transmitted within 10 cm of a passenger while operating below safety limits.