Characterization of novel Inductive Power Transfer Systems for On-Line Electric Vehicles

The Inductive Power Transfer System (IPTS) for On-Line Electric Vehicle (OLEV) developed at KAIST is fully characterized in this paper. The proposed IPTS includes Tesla's resonant transformers and show quite different characteristics comparing with conventional transformers. A current source instead of a voltage source is used for the IPTS at the primary side, and the system is fully resonated for maximum power delivery unlike other IPTS's. The proposed IPTS inherently has novel input/output characteristics. It is quite robust to abrupt the load change raised by the vehicle inrush or power fluctuation. Furthermore the output voltage of the IPTS is nearly constant regardless of output power, and the output current may increase regardless of source current. It is shown in this paper that the IPTS is equivalently an ideal voltage source, hence the output current can be infinite theoretically. The limiting factors in practice are found to be the resonant frequency variation and the parasitic resistances. It is thoroughly verified by simulations and experiments.