Modeling and Design of Contactless Sliprings for Rotary Applications

Contactless sliprings (CS) based on inductive power transfer (IPT) offer a safe and reliable power transfer solution for rotary applications. An accurate reluctance model for CS is presented in this paper along with the associated parameters identification, considering the partially linking effect of the magnetic flux. Aiming to obtain higher coupling coefficient and lighter weight, a design optimization for CS is also proposed by defining a new design parameter "zeta." Both simulations and experimental measurements are presented to verify the effectiveness of the proposed modeling method. The maximum errors (between the identified results and the measured results) of the mutual inductance, the leakage inductance, and the coupling coefficient are 8.72%, 7.12%, and 5.98%, respectively, when the gap is less than the core window width. Comparative studies among different modeling methods are carried out, which testify that the proposed method has the highest accuracy. Finally, a 1.5 kW IPT system employing the designed CS is fabricated for verification.