Tripolar pad for inductive power transfer systems

Abstract

Inductive Power Transfer (IPT) systems have been proposed in recent years as a safe, convenient and robust method of battery charging in EVs and robots. In an IPT system, the magnetic design of the primary and secondary pads is an important factor that determines the power transfer capability. This paper proposes the Tripolar Pad (TPP), a novel three coil magnetic pad utilising mutually decoupled coils. The TPP maintains tolerance to rotational displacements similar to nonpolarised pads, but uses polarised fields to improve power transfer. Simulation results are first shown in the paper and then validated by a scaled prototype.

Improvement of equivalent magnetic coupling coefficient of wireless power transfer system with multiwinding transmission coil

“…A number of studies were dedicated to improvement of magnetic coupling between primary and secondary sides of IPT systems; particularly, techniques were proposed recently to increase equivalent coupling coefficient of entire coil setup by using multiple windings …”

“…On the other hand, multiwinding configuration of the sending side combined with magnitude and phase control of current in each winding was proposed to increase equivalent coupling coefficient and to compensate for misalignment . However, Ref.…”

“…Thus, there are many previous reports on improving equivalent coupling coefficient of sending and receiving coils. However, the previous methods lack parameter design guidelines, while the influence of magnetic coupling between windings on equivalent coupling coefficient is unclear . Particularly, as regards IPT systems with multiple input and output windings, no methods were proposed, to our best knowledge, for improving equivalent coupling coefficient of entire coil system from the viewpoint of parameter design.…”

“…A number of studies were dedicated to improvement of magnetic coupling between primary and secondary sides of IPT systems; particularly, techniques were proposed recently to increase equivalent coupling coefficient of entire coil setup by using multiple windings. [10][11][12][13][14][15][16][17][18] Ref. 13 proposes an IPT system using repeater coils to absorb misalignment and to expand power transmission distance.…”

“…On the other hand, multiwinding configuration of the sending side combined with magnitude and phase control of current in each winding was proposed to increase equivalent coupling coefficient and to compensate for misalignment. [15][16][17][18] However, Ref. 17 explores winding configuration to obtain zero coupling between windings on the sending side, while no quantitative substantiation is provided for advantage of zero coupling.…”