A Hybrid Wireless Power Transfer System with High Misalignment Tolerance Using Diagonal Crossed Solenoid Magnetic Coupler*

Abstract

During wireless charging, misalignments commonly occur in the transmission between the transmitting and receiving pads, including misalignments in the forward, backward, lateral and vertical directions. Unavoidable misalignments can result in changes in system parameters, thus affecting charging performance. A novel diagonally crossed solenoid magnetic coupler (DCSMC) is developed as a solution. The DCSMC integrated into a wireless power transfer (WPT) system with a hybrid topology enables superior misalignment tolerance in the X, Y, Z and XY diagonal directions while maintaining load-independent voltage output characteristics. A simplified parameter design method is developed to optimize the misalignment tolerance performance of a hybrid WPT system in multiple directions. Finally, a hardware prototype of a WPT system is constructed with an operating frequency of 200 kHz and a power of 200 W. The experimental results show that the hybrid WPT system, operating under loads from 40 Ω to 80 Ω, can tolerate misalignments of ±90 mm (40.9%) in both the $X$ and Y axes, maintaining as small as a 5% fluctuation in output voltage. In addition, the WPT system can handle a maximum vertical displacement of +40 mm along the Z-axis and XY-diagonal misalignments of ±40 mm (12.8%).