Research On Wireless Power Transfer System Through Coupled Resonances

The wireless power transfer through coupled resonances is a new kind of wireless power transfer technique, which is based on near-zone electromagnetic field theory and resonant coupling theory and has the characteristics of high efficiency and mid-range power transfer. The new technique overcomes many shortcomings which belongs to the traditional power transfer and can transfer the power with high efficiency, so it has important scientific significance and research value.Compared with inductively coupled wireless power transfer, the wireless power transfer through coupled resonances has the longer transfer distance. It also has higher efficiency than the power transfer through electromagnetic radiation.The paper mainly researches on the power output and efficiency characteristics of the wireless power transfer system and analyses the relation between the output power and efficiency and the system parameters, which is proved by experiment.The main contents and conclusions of this paper are as follows:The model of wireless power transfer system is built by using coupling theory, which is used to analyze the relationship between the efficiency and the system parameters, so we can obtain the energy transmission conditions and maximum efficiency conditions.The circuit model of wireless power transfer is built by using Circuit analysis principle, which is used to analyze the relationship between the output power and circuit parameters, so we can obtain the maximum output power conditions.The resonant coupling wireless power transfer device is made, which includes high frequency drive power supply and transmitter and receiver coil. Using the design device, the power is transferred and can light a25W bulb which is8cm from the transmitter coil.The effect of frequency, drive voltage and transmission distance on output power and efficiency is obtained by experiment which also validates the theoretical analysis results.