A Robust Capacitive Power Transfer System via Fractional-order Autonomous Circuit

Capacitive power transfer (CPT) technique uses coupled metal plates for energy transmission, which has the advantages of negligible eddy-current loss and low weight. To achieve efficient power transfer, CPT system often adopts circuit resonance and impedance compensation, which are generally realized by integer-order components, such as inductors and capacitors. However, it remains a fundamental challenge to create a CPT system whose transfer efficiency and output power are robust against the variation of resonant frequency and the coupled plates’ relative position. Therefore, this paper proposes a robust fractional-order autonomous CPT system containing a fractional-order inductor. Theoretical analysis shows that the transfer efficiency and output power of the proposed fractional-order CPT system are inherently robust not only to the variation of the coupled plates’ relative position but also to the resonant frequency. In contrast, the transfer efficiency and output power of traditional integer-order CPT systems are sensitive to the resonant frequency. The available experimental results verify the effectiveness of the proposed system.