Wireless power transfer system for angled concave conditions utilizing quasi-bowl-shaped couplers

Wireless power transfer (WPT) is favored by consumers due to its convenience, safety, and flexible layout. Circular and rectangular coils are the most common coil structures in WPT systems. However, they are not suitable for installation conditions with angled groove areas such as railways, conveyors, and so on. To fully utilize installation space and to improve transfer efficiency, this paper has proposed a quasi-bowl-shaped (QBS) magnetic coupler, which can suitably fit on angled grooves. First, a QBS coupler model was presented. Second, formulas of its spatial magnetic field density were derived. Third, the influences of the bending distance and bending angle on the coupler coefficient were analyzed. Fourth, five magnetic core types were presented and analyzed for coupler optimization. Finally, QBS WPT performances were tested on a newly built experiment platform. Experimental results show that the QBS coupler can realize a constant transfer efficiency of 92.36% at an axial distance of 6 cm, and it can realize a constant transfer efficiency of 84.17% at an axial distance of 10 cm.