Wireless Power Transmission-Based In-Wheel Switched Reluctance Motor Drive System With an x-Type Converter

This paper proposes a wireless power transmission (WPT)-based in-wheel switched reluctance motor (IWSRM) drive system, which uses an x-type converter at the motor side with charging function. In this system, a single frequency WPT subsystem with one transmitter coil and one receiver coil is used to completely isolate the DC power side from the motor side, and realize a transmission voltage gain of 1 by incorporating the symmetrical LCC-S network, which has the advantage of constant voltage gain when load changes. Be different from asymmetric half-bridge (AHB) converter, at the motor side an x-type converter with minimum number of active power switches is employed to connect the WPT subsystem, in which one power switch and one diode are used for each phase with independent control. The number of power active devices are reduced by half compared to AHB converter. Two freewheeling modes are analyzed for the drive system: the resistance freewheeling mode and the battery charging freewheeling mode. An experimental setup for a WPT-based three-phase 18/24-pole IWSRM system was built and tested. The simulation and experiment results of the system under two freewheeling modes are presented to validate the analysis and effectiveness of the system. The DC-to-DC efficiency is achieved over 96% with 100 mm air gap and the system efficiency is achieved up to 82% with the battery charging freewheeling mode.