Crossed dipole coils for an omnidirectional wireless power zone with DQ rotating magnetic field

Crossed dipole coils for the wide-range 3-D omnidirectional inductive power transfer (IPT) are proposed. Free positioning of a plane receiving (Rx) coil is obtained for an arbitrary direction within 1m from a plane transmission (Tx) coil. Both the Tx and Rx coils consist of crossed dipole coils with an orthogonal phase difference; hence, a rotating magnetic field is generated from the Tx, which enables the Rx to receive power vertically or horizontally. Chronic installation problems associated with conventional coils for achieving omnidirectional characteristics, i.e. volumetric coil structure and high system complexity, can be resolved by the proposed plate type crossed-dipole coils. Simulation-based design of the proposed crossed dipole coils for a uniform magnetic field distribution is provided, and the 3-D omnidirectional IPT is experimentally verified by prototype Rx coils for a wireless power zone of 1 m³ with a prototype Tx coil of 1 m² at an operating frequency of 280 kHz, meeting the Power Matters Alliance (PMA). The maximum overall efficiency was 33.6% when the input power was 100 W.