Wireless Power Transfer (WPT) systems for electric vehicles (EVs) enable dynamic charging while in motion and offer a promising solution to concerns of limited driving range and long charging times. Although inductive WPT systems have been widely studied, they are bulky, costly, and constrained by ferrite losses. Capacitive WPT systems avoid ferrites and are lighter and less expensive, but when embedded in pavements they suffer high dielectric losses due to fringing electric fields at the coupler edges. This digest proposes novel curved couplers that suppresses fringing electric fields, thereby reducing losses in pavement materials. A 6.78-MHz, 1-kW capacitive WPT system using the proposed curved couplers is designed and analyzed. The optimized curved couplers achieve a 36% reduction in pavement losses and a 40% reduction in surrounding fringing fields compared to conventional flat couplers, while also lowering pad thickness and weight. Two 6.78-MHz 1-kW experimental prototypes—one using flat couplers and the other using the proposed curved couplers—are constructed and tested within asphalt.
