Optimisation analysis of coil configuration and circuit model for asymmetric wireless power transfer system
The authors present a new asymmetric structure using an optimisable coil configuration and circuit model to eliminate frequency splitting and increase high-efficiency transfer distance in wireless power transfer (WPT) via magnetic resonance coupling. A pair of non-identical coils is proved theoretically and optimised to limit the coupling coefficient. The series–shunt mixed-resonant circuit structure is adopted to promote the performance of WPT system. The advantages and characteristics of the asymmetric system using mixed-resonant circuit structure based on appropriate non-identical coils are depicted by numerical calculation and simulation. Moreover, the WPT system is finally set up to verify the theory prediction. All the calculated and experimental results show that frequency splitting is suppressed in close distance effectively. Moreover, the high-efficiency transfer distance is proved to exceed the triple diameter of receiving coil. Therefore, a relatively high-efficiency and long-distance WPT system, which can be a good candidate for charging portable electronics, is obtained by selecting suitable circuit parameters and appropriate non-identical coils.
