Design of a Nonlinear Wireless Power Transfer System with Wide Range of Excitation Voltage

Magnetic coupling wireless power transfer (MC-WPT) has great potential in various applications such as the charging of electric productions or biomedical implants. The MC-WPT system based on nonlinear resonance has been proved to be a promising technique due to its robustness to the variation of resonant frequency. By utilizing a nonlinear component, it has been found that high power transfer efficiency can be maintained even when the frequency deviates from the original resonant frequency. The MC-WPT system is generally operated in periodic sinusoidal state. In this work, the characteristic of a nonlinear MC-WPT system is analyzed when the equivalent excitation voltage changes. The result shows that the system varies from periodic state to chaotic state with the increase of excitation voltage and operates in periodic sinusoidal state merely in a small range. In the periodic non-sinusoidal state, a filter is introduced and designed which ensure the normal operation of the nonlinear MC-WPT system in a wide range of excitation voltage.