Strong misalignment tolerance wireless power transfer with active adjustment of magnetic shielding

Abstract

The variation of mutual-inductance is the essential reason for fluctuation of transmission power and efficiency during wireless power transfer (WPT) misalign. To maintain output power stability, current methods, such as primary regulation, secondary conversion, magnetic coupling mechanism (MCM) optimization, and compensation topology design, have not changed the characteristic of mutual-inductance changing with misalignment. A strong misalignment tolerance WPT system based on the influence of high permeability magnetic materials on equivalent electrical parameters of MCM is proposed. When the primary and secondary sides of MCM shift, the relative distance between magnetic shielding and coil (RDMSC) is adjusted to maintain the stability of mutual-inductance. The transmission efficiency and power are not affected by misalignment. Alternatively, RDMSC can be actively adjusted to meet the various needs of diverse loads at different times. Simulations and experiments are conducted. The effectiveness of the proposed scheme that RDMSC is actively adjusted to overcome misalignment is verified. This is a new method based on active adjustment of spatial electromagnetic coupling, which provides a new idea for WPT to overcome the influence of misalignment and maintain stable output.