A Novel Type of Phase-Shift Controlled Wireless V2H with Dual-Active Single-Ended Converters

Abstract:
This paper deals with bidirectional WPT apparatus for V2H using simple and compact single-ended converters with a new control method. Firstly, the operation of bidirectional wireless power transmission and the configuration of the wireless V2H system is illustrated. Secondly, a design strategy for satisfying the target specification of 3kW transfer power and 85kHz operating frequency are described. Then, problems about stability of operating frequency and robustness to power component variation are discussed from a practical point of view. Illustrated is that the transfer power is essentially decided by a phase difference between the power feeding and the power receiving circuit. Finally, proposed is a variable-power constant-frequency single-ended bidirectional converter with dual-active phase-shift control. Since the wireless V2H system can be controlled under a constant operating frequency, it is easy to confirm the specified frequency band to international standards. The high-power wireless transfer is achieved by the optimum phase difference in spite of the low coupling coefficient between transfer coils. Furthermore, the proposed system secures the stability of the power transfer operation against the variation of parameters as compared with the previous frequency-controlled system. In addition, an improved system with a new PLL control which doesn’t need phase detector is discussed. Then, the newly developed low-cost single-ended wireless V2H system is suitable for mass production.