Wireless Power Transfer System for Automatic Revolving Doors

In this paper, we propose a novel wireless power transfer (WPT) system with fixed transmitting (Tx) coil and rotating receiving (Rx) coil used in automatic revolving doors. The WPT coils provide a high coupling and achieve a high efficiency against rotation. The coils are wound on coaxial structures similar to a pivot joint. The mutual inductance (M) between the coaxial windings is derived and validated by simulation, calculation, and measurement results. Design procedures of the coils are discussed. Finally, the WPT windings were fabricated. Experiment results are in good agreement with the calculation and simulation results.