LCL pick-up circulating current controller for inductive power transfer systems

This paper proposes a fast switching control topology for a series-parallel tuned LCL pick-up. This topology employs a similar idea to the traditional controlled rectifier to regulate the average output current through the rectifier. The proposed topology is able to provide the LCL pick-up with a smooth power transition between fully on and fully off. Also, it is able to achieve power regulation while allowing some variance in mutual coupling with the track without overloading the power supply. The normalized reflected impedance of the proposed controller back onto the primary track is first discussed in relation to simulation results. Then a 2.5 kW 50V output prototype is constructed and tested that achieves an efficiency of 88% at full load and 85% at half load. The reflected impedance of the prototype is also calculated using a normalized graph. It demonstrates that mistuning of the primary track with the associated reflected reactance has little input on system operations.