A Novel Long-Distance Wireless Power Transfer System With Constant Current Output Based on Domino-Resonator

In this article, a novel long-distance wireless power transfer (WPT) system that achieves excellent constant current (CC) output based on a domino-resonator is proposed. A thorough mathematical model of the n-coil domino WPT system is established, and the methodology of calculating and choosing the operating frequency in the CC mode is put forward to achieve high efficiency and the best stability. The zero-phase-angle (ZPA) condition is proven to be realized, in the meantime, by theoretical derivation. The phenomenon that operating frequency slightly shifts away from the resonant frequency in the CC mode due to the magnetic coupling between nonadjacent coils is studied. The efficiency of the system is evaluated. Moreover, system efficiency can be further improved by optimizing the number of coils and layers when the transfer distance is fixed. An experimental setup with an output current of 0.6 A has been built to demonstrate the validity of the proposed system. The experimental results show that the maximum system efficiency of the experimental setup in the CC mode can achieve 70% at the transfer distance of 0.7 m when the number of the coils is 8 and the radius of the coil is 100 mm.