Research On Key Technology In Magnetic Resonate Wireless Power Transmission System

Compared to traditional contact charging, wireless power transmission technology has advantages on flexibility and reliability to use, adaptability to environment that attracts many experts and scholars to study it. Among them, magnetic resonance WPT technology is of great value and implications for the development of WPT technology because of its high transfer performance which will be an important direction in the field of WPT technology.Firstly, the dissertation introduces the concept and classification of WPT technology, reviews the developing history of magnetic resonance WPT technology, generalizes the working principle, research development on key technologies and practical application, points out that non-contact transformer is critical to the optimization of magnetic resonance WPT system.Secondly, expression of voltage gain, transfer power and efficiency has been derived by mutual inductance model, and the relationship between the transmission characteristics and key parameters has also been analyzed. With the research on new structure and quality factor model of coils, method of the design load and high frequency, the transmission characteristics of magnetic resonance WPT system is optimized.The maximum voltage gain and output power design method based on the optimal distance point is also put forward in this dissertation. Meanwhile, the research on the efficiency evaluation in Class-E converter based on Ga N devices has shown that Ga N transistor can obviously brings higher transmission efficiency, smaller size and lower cost in Class-E converter due to the lower Rds(on) and the gate charge(Qg).Thirdly, a magnetic resonance WPT area with four excitations has been promoted to build the omni-directional magnetic resonance WPT area. By changing winding connection of the excitation coils, the magnetic field distribution in wireless power supply area has been changed which forming a magnetic field of the enhanced area and blind area. The location of the electrical terminals can be shifted to improve power transmission efficiency, according to the magnetic field distribution in different winding connections which has been analyzed and summarized.Last but not least, the transmission characteristics, ways to optimization and design process of the system are summarized, which will help to the further research and application of magnetic resonance WPT technology.