Surrounding Active Shielding Coil Design and Efficient Multiobjective Optimization for WPT

Abstract

Aiming at the problem that the leakage magnetic field (LMF) generated by wireless power transfer (WPT), a surrounding active shielding coil structure, and its fast multiobjective optimization design method is proposed. First, considering the problem that active shielding can reduce the efficiency of WPT, a surrounding active shielding coil structure that is inversely connected in series to the WPT coil is proposed, and the inner shielding coil compensates for the efficiency. Then, taking the efficiency of the WPT and the maximum magnetic flux density of the measurement surface as the optimization objectives, combining the data-driven polynomial chaos metamodel method and the optimization method based on the non-dominated sorting genetic algorithm, a fast multiobjective optimization design of the surrounding active shielding coil structure is achieved. Finally, an experiment was conducted using a 300 W WPT. At fixed observation point, the surrounding active shielding coil structure proposed in this article reduced the LMF by 86.97%, and the induced electric field strength of the human body exposed to the LMF was reduced by 65.40%, while the efficiency of the WPT was only reduced by 0.28%, proving the surrounding active shielding coil and its efficient design method are effective.