Wireless Power and Drive Transfer Using Orthogonal Bipolar Couplers and Separately Excited Modulation

Abstract

This article proposes and implements a novel wireless power and drive transfer system using orthogonal bipolar couplers and separately excited modulation (SEM). Specifically, two bipolar coils are orthogonally integrated and naturally decoupled to form a compact magnetic coupler which will be utilized in the transmitter and receiver, respectively. The key is to employ the SEM to alternatively energize bipolar coils in the transmitter while self-driven circuits in the receiver can directly extract the drive information to control receiver-side switches. Consequently, the concurrent wireless power transfer and wireless drive transfer can be skillfully realized via the shared transfer channel at the single resonant frequency. Moreover, the proposed system can effortlessly achieve the wireless dc motor drive with the capability of bidirectional motion, or the wireless ac motor drive with the variable-voltage variable-frequency control. Besides driving the dc and ac motors, a 200-W prototype is constructed with the transmission efficiency of 89.5% over the transfer distance of 100 mm for a resistive load of 40 Ω. Both theoretical and experimental results are provided to validate the feasibility and flexibility of the proposed system.