Experimental evaluation of A 3-kW high-efficiency inductive contactless power transfer (IPCT) system for electric vehicles

A 3-kW high-efficiency inductive-contactless-power-transfer (ICPT) system for electric vehicles was constructed and evaluated. The maximum efficiency of the prototype system is 93.6% for a 20-cm air gap. Moreover, over 90% efficiency is maintained across a wide range of air gaps at full load. To clarify the problem of improving efficiency under a wide range of air gaps, the loss characteristics of the prototype (which vary according to air gap) were analyzed. In addition, the magnetic-field distribution around the contactless transfer coil was evaluated by simulation and experimental measurements.