Wide-range ubiquitous Wi-power zone by magnetic shielding

Wide-range ubiquitous wireless power environment, called as ubiquitous Wi-power zone, where any electric devices can be charged by 3D-omnidirectional wireless charging, is newly proposed in this paper. By virtue of the proposed Direct-Quadrature (DQ) transmitting (Tx) coils with magnetic shielding, ubiquitous Wi-power zone having transmitting (Tx) coils can be provided over wide-range 3D spaces, which will be a next generation wireless power transfer (WPT) as internet of things (IoT) and sensor technologies evolve. Thus, a number of electric devices can be simultaneously charged during operations in this area. To create the proposed ubiquitous Wi-power zone with high power efficiency, providing with an evenly distributed magnetic field, various candidates behind DQ Tx coils for magnetic shielding were evaluated and experimentally verified in this paper; hence, core loss of the proposed Tx coils can be significantly reduced for high efficiency and magnetic shielding behind Tx coils is guaranteed without affecting front side magnetic field in the proposed Wi-Power zone. The proposed Tx coils can be modularized for easily installation in different size of 3D places by each Tx coil modules in order to commercialize the proposed Wi-power zone. A prototype of 80 cm × 80 cm DQ Tx coils, including 25 pieces of modularized Tx coils for an uniformly magnetic field distribution, was built and experimentally verified for the proposed Wi-power zone. As a result, measured magnetic flux density at z
₁
= 0.25d
_l
is always higher than -3dB of maximum magnetic flux density.