An Inductive Power Transfer System Design with Large Misalignment Tolerance for EV Charging.

Inductive power transfer (IPT) technology is becoming more and more attractive for electric vehicle charging due to its safe, flexible and convenient features. The main drawback of IPT system is the large leakage inductance, especially when there is misalignment between the pads. The misalignment reduces coupling and reduces the overall efficiency. This paper proposes an IPT system with large misalignment tolerance which combines the characteristics of a new solenoidal-bipolar transformer and a parallel circuit topology for the secondary side. The system design and performance are simulated with a 3D finite element modeling (FEM) tool and experimentally verified on a 3kW prototype. A 350 mm misalignment tolerance range for either lateral or vertical direction is achieved with a 600 mm2transformer and a 200 mm air gap.