Coupling study of a rotary Capacitive Power Transfer system

In this paper a new technology termed Capacitive Power Transfer (CPT) is investigated to achieve contactless power transfer. Compared to traditional Inductive Power Transfer (IPT) technology, the advantages of CPT include the ability to supply power through metal barriers, reducing standing power losses, and alleviating EMI (Electromagnetic Interference). Electric coupling is a key part in a CPT system as it dominates the maximum power transfer capacity and the performance of the system. Different applications can have very different coupling structures and power level requirements. This paper proposes two types of coupling structures, disk and cylinder, for a rotary CPT system application. The system frequency, maximum output power, and power losses based on the cylindrical structure which has a larger coupling capacitance are analyzed. Simulation and experimental studies are carried out to verify the proposed coupling configurations.