Magnetic design of a three-phase Inductive Power Transfer system for roadway powered Electric Vehicles

Inductive Power Transfer (IPT) is a viable method for recharging and powering Electric Vehicles (EV) along a roadway since it is safe, efficient and convenient. This is however, a demanding application because power needs to be transferred over relatively large air gaps of 150-200 mm while allowing sufficient horizontal tolerance across the width of the lane, to enable an unguided vehicle to receive full power. The design of the power track is critical to large scale implementation, to ensure that losses and cost are minimised while maximising horizontal tolerance. The approach used in this paper overcomes the limitations of earlier track designs and allows designers to increase horizontal tolerance with minimal cost, enabling an EV roadway system to be considered in future. A 2.5 m long track is built for lab testing and compared to a 3D finite element model, after which, the design is refined via simulation to meet the tolerance and power requirements of an EV.