Research on characteristic and experiment device of wireless power transfer

In order to solve problems such as short distance existing in the passive tag´s wireless power transfer with loose coupling of electromagnetic, an improved strong magnetic coupling resonance energy transfer method for tags based on high Q value was proposed. Theory analysis and simulation of wireless power transfer efficiency and Q value were done based on coupling model theory and resonance circuit theory. Two improved models based on series resonance circuit and parallel resonance circuit were given and the corresponding experiment testing devices were designed. The experiment results show that Q value is increased by adding the resonant coil, the maximum transmission distance under the two improved methods is three size of that one under the basic resonance, and the transmission efficiency is four size of that one under the basic resonance. Moreover, the transmission efficiency of parallel resonance has been improved obviously. The method´s validity is proved at last.