A Cubic Wireless Charging Container System With Highly Uniform Magnetic Field Distribution

This article introduces a spatial wireless charging system featuring a cubic transmitter (Tx) designed for strong and uniform magnetic field distribution inside the Tx container. The Tx coils are wound with two separate wires on the exterior surfaces of the container, employing a decoupled structure. The rotational current control method is employed for the Tx resonators along the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</i>- and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</i>-axes to improve the uniformity of the magnetic field distribution. Within the container, planar receiver coils can achieve consistent charging with stable received voltage and maximum efficiency, regardless of the movement along the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</i>- or <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</i>-axis, self-rotation at various positions, or revolution around the central point of the container. Practical results confirm that the proposed design exhibits smaller deviations in output voltage and overall efficiency (from dc to dc) compared to the conventional design for spatial wireless power transfer systems operating at 200 kHz and 401 kHz across the four different scenarios.