Determining the variable inductance range for an LCL wireless power pick-up

Variable inductor control of an LCL wireless power pick-up is an effective method for regulating power flow to maintain the load voltage constant. However, how much variation is needed to cover the full control range remains an unsolved question. In this paper, thorough analytical and numerical analysis has been undertaken to determine the variable inductance range by taking practical circuit variations such as tuning capacitor and load resistance into consideration. The worst scenarios corresponding to the maximum and minimum inductance of the variable inductor are identified in the case of combined maximum/minimum tuning capacitance and load resistance. These results are very useful for controlling the variable inductor and its controller in order to achieve a robust wireless power supply under various circuit parameters and load variations.