Innovative shielding technique for wireless power transfer systems

The High Magnetic Passive Loop (HMCPL) technique is proposed as an innovative passive shielding system to mitigate the undesired dispersion of the magnetic field produced by a wireless power transfer (WPT) system, thus reducing the risk of hazardous human exposure. The magnetic structure is described both in terms of lumped parameters circuit, useful for sizing, and in terms of a geometrical representation solved by finite element method, useful to assess the field attenuation effects. Sizing of the resonance capacitors in the shielded WPT structure is approached as a Pareto optimization problem and solved via genetic algorithm. HMCPL shielding design guidance is provided to reduce the magnetic field emission in the surrounding environment. Furthermore, the influence of the shielding on the performance of the WPT system is also evaluated. Penetration of WPT technology for transportation is limited by health and EMC issues related to exposure to magnetic fields. A shielding solution is proposed and optimized to achieve shielding effectiveness and retain good transmitted power. Misalignment effects are evaluated.image