Design of a New Magnetic Coupling Structure for High-Speed Rotating Wireless Power Transmission System

An efficient, stable and reliable wireless slip ring magnetic coupling structure is designed for high-power, high-frequency and high-speed applications to completely replace the mechanical slip ring for energy transmission. Traditional coupling structures have the drawbacks such as low coupling coefficient, parameter fluctuation, electromagnetic interference and too heavy rotor. This paper proposes a novel magnetic coupling structures with C-shaped magnetic cores, and analyzes their superiority over the traditional structures. A comparison is conducted between the proposed structures and two widely-used traditional structures on the market, which demonstrates that the novel structure with C-shaped magnetic cores and coaxial winding arrangement has higher coupling coefficient, more stable electromagnetic parameters, lighter rotor weight, and more easily shielded near-field electromagnetic interference. In order to verify the proposed structure, a 1:1 experimental prototype is fabricated. With the stable rotation of 5r/s, the system completely overcomes the problem of parameter fluctuation caused by rotation offset.