Nicholas Athol Keeling

A Unity-Power-Factor IPT Pickup for High-Power Applications

This paper describes the design of a new unity-power-factor inductive-power-transfer (IPT) pickup using an LCL tuned network for application in high-power systems. This new topology has the potential to increase the efficiency and reduce the cost of high-power pickups by minimizing the reactive currents in the pickup coil and the reflected VAR loading on the power supply. In a practical system, the rectifier and associated processing circuitry distorts the current waveforms, adding an effective inductive loading to the pickup circuit. A series compensation capacitor is added to correct this loading. A design strategy is developed for the new topology, and two example circuits are constructed and compared experimentally with a traditional parallel-tuned (LC) pickup operating on a monorail-based IPT system.

Variable tuning in LCL compensated contactless power transfer pickups

This paper analyses the effects of tuning deviation in the resonant tank of an LCL Inductive Power Transfer (IPT) pickup. It also proposes a method of active tuning which maintains unity power factor at the input to the pickup. By varying the second inductor in the LCL network, variations in the tuning capacitor can be compensated which also acts to increase the output power to the load after the retuning action. The power increase is limited by the available control action and component rating. A self tuning pickup has been built using a saturable inductor to vary the impedance of the tuning components. The pickup successfully maintains unity input power factor when the tuning was deliberately deviated.

Unity power factor inductive power transfer pick-up for high power applications

This paper describes the design of a new unity power factor inductive power transfer (IPT) pick-up using an LCL tuned network for application in high power systems. This new topology has the potential to increase the efficiency and reduce the cost of high power pick-ups by minimizing the reactive currents in the pick-up coil and reflected VAR loading on the power supply. In a practical system the rectifier and associated processing circuitry distorts the current waveforms, adding an effective inductive load to the circuit. A series compensation capacitance is added to correct this distortion. A design strategy is developed for the new topology and two example circuits are constructed and compared experimentally with a traditional parallel tuned (LC) pick-up operating on a monorail based IPT system.