A Misalignment-Adaptive Wireless Charging System for Inspection Robots

In this paper, a misalignment-adaptive wireless charging system for inspection robots (IRs) is proposed, which has auto-alignment capability in <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</i> axis and high coupling tolerance in <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</i> axis. A reconfigurable secondary compensation circuit is designed to work initially in the inductor-capacitor-capacitor series (LCC-S) mode for magnetic field auto-alignment, and it is then switched to LCC-LCC topology for wireless charging. The Q-coil is used in a reconfigurable coupling structure to adjust the IRs position for auto-alignment and it is also used as the compensation inductor for wireless power transfer. The DD-coil in secondary side is used to achieve high coupling tolerance capability in <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</i> axis. A laboratory prototype with an output current of 22A and output voltage of 52V is built, and practical results show that the system can achieve an alignment accuracy of ±5mm in <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</i> axis, and the output current fluctuation of the system is ±3.2% when the misalignment ratio along <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</i> axis is 40%.