Concurrent Wireless Power Transfer and Motor Drive System With a Single Converter

This article presents a novel system to utilize conventional motor drives for wireless power transfer (WPT) to supply auxiliary systems, such as Internet-of-Things devices or sensors in rotating systems. The conventional method is to use a slip ring, which reduces reliability, or to use an extra high-frequency converter next to the motor drive, which increases the system cost. The development of wide-bandgap devices such as gallium nitride and silicon carbide transistors has increased the switching frequencies of motor drives with lower switching losses. The voltage harmonics of these high switching frequencies can be utilized to excite a WPT system while the low-frequency modulated current can still be used to drive the motor. In this article, the relation between the motor drive and the WPT system is investigated under different operating conditions, and the proposed method is experimentally verified with a GaN-based full-bridge converter, a series–series WPT system at 50 W, and a dc motor at 500 W. Thereby, a cost-reduced contactless slip ring was obtained using the concurrent conventional motor drive and inductive power transfer systems.