A Repeater-Based Dynamic Wireless Power Transfer System Using Controllable Detuning Rate for Constant Output Power

Dynamic wireless power transfer (DWPT) system has become an ideal solution for electric vehicles as it can keep the power supply and reduce the battery volume. However, it hasn’t been popularized in electric vehicle charging, due to the high construction cost, low charging efficiency, and larger power fluctuation. This paper proposes a repeater-based DWPT system with a controllable detuning rate to achieve constant output power during the whole movement process. The switched capacitor is introduced in the repeater coil for the adjustment of its detuning rate. By analyzing the relationship between the output power and the mutual inductances among the transmitter, repeater, and receiver coils, a detuning rate control strategy is proposed to reduce the power fluctuation. Moreover, strategy proposed control strategy can minimize the no-load loss of the repeater coil. An 85 kHz simulated DWPT system is established for theoretical verification. The simulation results show that the proposed system can achieve an approximately constant output power of 545 W during the whole dynamic process, with a maximum fluctuation of less than 5%.