| Wireless power transfer(WPT) technology transfers power from the source to the load by magnetic or electric coupling, without electrical connection. Inductively coupled power transfer(ICPT) technology, as the most mature one, has a broad prospect for application.The efficiency of power converter, as an essential part of WPT, greatly affects the efficiency of the whole system. Synchronous rectification(SR) technology replaces diode with low-resistant MOSFET. How to combine SR and ICPT technology is the main research in this thesis.Firstly, based on the model of ICPT system, this thesis researches the output characteristic of ICPT system with four compensation topologies. It comes to a conclusion that the output voltage is sensitive to the load, which is difficult for the design of SR. In order to solve this problem, this thesis puts forwards two kinds of new compensation topologies with stable output voltage gain. Then we design an ICPT system with stable output based on one of them.Secondly, we analyze the loss of diode and MOSFET, which concludes that SR technology is suitable for low-voltage and high-current systems. By the research of the driving ways of SR, this thesis points out the limitations of traditional driving of SR when used in ICPT system.Finally, this thesis puts forwards a new SR control block, which is suitable for ICPT system. Compared with diode rectifier, the efficiency of ICPT system with SR is improved by 7.4% in the same load, which verifies the correctness and effectiveness of the SR control block. |
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