The Optimal Design of the Segmented Primary Track for Inductive Wireless Power Transfer System

The inductive Wireless Power Transfer (WPT) system used for EV or rail transit often subdivides the long primary track into many short segments in order to decrease the primary track loss. When the vehicle is running into the transition region between two neighboring segments, the induced voltage often fluctuates. This paper proposes several primary track design schemes using overlapped or twisted coils. The uniformity of the magnetic field along the track is improved, the variation of the mutual inductance between the primary track and the secondary coil is reduced, and the stability of the output voltage can be enhanced.