A bipolar primary pad topology for EV stationary charging and highway power by inductive coupling

Electric vehicles have been rapidly gaining in popularity in recent years, and with them inductive charging solutions. The ideal stationary charging system requires no input from the user, and places as few restrictions on either parking location, or environmental conditions (i.e. rain or snow) as possible. The success of inductive charging systems is contingent largely on the design of the magnetic coupling components; i.e. the track pad and the pickup. This paper details a new topology for the track pad, consisting of two largely coplanar, partially overlapping coils positioned such that there is no mutual inductance between them. This arrangement prevents interaction of the two coils, and allows the currents within them to be independent in both phase and magnitude. By controlling the phase and magnitude of the two coil currents, the magnetic field can be shaped to assist in power transfer to a pickup underneath an EV.