Improved Coupling Design of Contactless Slipring for Rotary Applications

Contactless sliprings based on inductive power transfer (IPT) are a preferable alternative to mechanical sliding contacts for power transfer in rotary applications. However, existing contactless sliprings suffer from low-magnetic coupling coefficient k, which results in limited power transfer capability. This paper presents an improved coupling design method of IPT-based contactless slipring systems to increase the coupling coefficient within the same physical size of the existing system with U, E, and pot-core geometry configurations. It has been found from the finite element method study that k increases about 21.3%, 45%, and 20% for UU, EE, and pot-core arrangements, respectively, within the defined dimensions. The proposed EE and pot-core coupling arrangement have been verified by experiments and it has been shown that k is increased about 33% for EE and about 22% for pot-core arrangements.