Rotary capacitive wireless power and signal transfers for sensing applications onboard trains

This work shows a novel solution that allows contactless capacitive signal and power transfers among bodies in relative rotation. After a first presentation of the simple working principles of the system and its features, the proposed capacitive wireless transfer is designed and applied to a real case scenario. Namely, the goal is to use the same capacitive channel for both supplying sensors and a microcontroller, but also to exchange data between the two bodies. The paper shows simplified analytical computations, and the results of finite-elements simulations run during the sizing process. The power transfer capabilities are verified through a simulation involving power components and including estimated non-intentional cross-couplings between the plates of the capacitors.