Active resonance wireless power transfer system using phase shift control strategy

Conventionally, both the primary side and the pickup side need series or shunt capacitor compensation to increase transmission efficiency in a wireless power transfer system. In this paper, a wireless power transfer system with an active resonance circuit is proposed. Comparing the diode based rectifier on the pickup side in traditional wireless power transfer systems, a PWM rectifier is exploited for several advantages. The compensation capacitor on the pickup side is replaced by the active resonance circuit for reactive power compensation. Furthermore, the low power transmission efficiency, which is caused by the compensation capacitor malfunction and the resonance tank detuning, could be alleviated in the proposed system. A phase shift control technique is adopted to regulate output power when input power varies. The mathematic model of the propose system is presented, and the influence of parasitic parameters are also analyzed to reach a more precise performance analysis. A 500W prototype is built, and the experimental results are provided to validate the theoretical model and the effectiveness of the system.