Capacitive Wireless Power Transfer System Applicable to Existing Charging Systems: Experimental Verification

This paper proposes a capacitive wireless power transfer (WPT) system capable of providing a utility-frequency output, which makes it suitable for integration into existing charging systems. The proposed system transmits power by directly injecting high-frequency waves into full-wave rectified sine waves. Therefore, this system does not require a capacitor in the DC link. On the secondary side, the waveform is regenerated to a full-wave rectified sine wave through a diode rectifier and a filter. The utility-frequency output is obtained by the unfolder on the secondary side without PWM. The fundamental characteristics of the proposed WPT system have been demonstrated with the prototype. In particular, the proposed system achieved a utility-frequency output with an input current total harmonic distortion of 4.10%. Furthermore, the performance of voltage stabilization with misaligned transmission couplers through variable-frequency control was found to be up to 11.2%.