Anti-Offset Wireless Power Transfer System Based on Variable Inductor
摘要
In recent years, wireless power transfer has been widely studied for its advantages of safety, convenience and intelligence. However, in the actual working scene, the horizontal or vertical offset of the receiving coil may cause a large fluctuation in the output voltage of the system, which seriously affects the life of the load, and the surge of the primary side current leads to the heating of the switch and even the overcurrent of the device. Therefore, this paper proposes an anti-offset control strategy based on adjusting the variable inductor to compensate for the surge of the primary side current and the fluctuation of the output voltage caused by the coil offset. In this paper, a detuned series-series anti-offset wireless power transfer system with variable inductor added to the secondary side is designed. The variable inductor is adjusted by changing the permeability of the variable inductor. Based on the adjustment of the variable inductor, the output voltage is constant when the coil is offset and the primary side current is reduced. The control strategy does not require wireless communication. Finally, a 600 W wireless power transfer system with stable output voltage of 72 V is built. The experimental results show that the tolerance range of the system in the horizontal direction is 0–12 cm, and the tolerance range in the vertical direction is 5–11 cm, and the current of the transmitting coil is reduced when the coil is offset. The system improves the freedom and stability of the wireless power transfer system.