Current balance control strategy for inductively coupled power transfer system with parallel pickup modules

To transfer large power in inductively coupled power transfer (ICPT) system, parallel secondary pickups are adopted. Because of the error of installation and measure, the parameters of parallel pickup modules are not completely consistent, resulting in the current unbalance or even over- current in parallel modules, which will damage the elements like resonant capacitance, even destabilize the system. This paper presents a novel current balance strategy to balance the current of parallel pickup modules caused by inconsistent parameters in ICPT system. The circuit model of ICPT is analyzed firstly and equivalent resistance is derived in the parallel multi-pickups system. To transform impedance, the BUCK circuit is introduced in secondary circuit. The simulation results are presented to show the correctness of the theoretical analysis and the effectiveness of the control strategy.