The Research Of Critical Application Technical Issues To Contactless Power Transfer System

With the development of modern electrical technology, the application trend of the non-contact power transmission technology in oil drilling, mining operations, household appliances, artificial organs, electric cars and other areas of the power supply is increasingly obvious. Many factors of iron core structure, air gap distance, power supply frequency, transmission efficiency and power level are mutual constraint and mutual influence in the design of contactless power transfer device, and "adjust measures to local conditions" must be considered in the contactless power transmission device design. The key technical problems of restricting the non-contact power transmission technology application are researched based on the research and analysis of contactless power transfer technology application situation and development trend.First of all, the basic principle of resonant non-contact power transmission technology is analyzed with coupled-mode theory, and design method of a kind of small power resonant contactless power transfer device is put forward based on self-control type high frequency resonant inverter circuit, and no-load and load test of the completed small power resonant contactless power transmission device are implemented, and it is analyzed that the output voltage and transmission efficiency are influenced by the launch coil, the receive coil and the alignment angle.Secondly, various units of the induction contactless power transmission system of loosely coupled transformer, capacitor compensation circuit, rectifier filter circuit, high frequency inverter circuit, RCC voltage regulation circuit and so on are discussed and analyzed from the circuit structure, working principle and model parameters, etc.. A small power induction contactless power transmission device design is given and tested, and it is analyzed that the output voltage and transmission efficiency are influenced by the air gap and the change of frequency.Again, finite element simulation analysis is implemented in view of the key components "loosely coupled transformer" of the induction contactless power transfer, and different excitation effect with different iron core structure of loosely coupled transformer is compared; The cylindrical loosely coupled transformer and its modified structure design are put forward in the drilling tool non-contact power supply unit, and the simulation analysis and comparison are made on the effect of excitation; Combination of loosely coupled transformer circuit and magnetic circuit model, relationship between output voltage, work efficiency and the power supply frequency are analyzed for the improved cylinder loosely coupled transformer, and the optimum power supply frequency is determined.Finally, in order to further improve the loosely coupled transformer coupling coefficient, reduce the magnetic flux leakage, the idea of the combined transmitter coil excitation are put forward, and the excitation structure of the line honeycomb plate type structure of loosely coupled transformer is designed, and the numerical solution method to mutual inductance of two PCB tracks windings based on the Von Neumann Formula is Given, and finite element analysis is carried out on the excitation effect, and it is analyzed that the magnetic flux density of planar and spatial distribution are influenced by coil number of turns, the structure of the iron core, layer number of coil and non-uniform excitation parameters; Two kinds of modified composite honeycomb structure of loosely coupled transformer excitation are put forward based on the above situation, and The influence of parameters such as spacing of the coil, coil width, center around coil size and location of auxiliary coil parameters aiming at "cylinder" and "laminated" type combined excitation structure on the excitation effect is analyzed.The key restricting technical problem application of the non-contact power transmission technology are discussed from the resonant and the induction contactless power transmission technology in this paper. Design method of contactless power transfer device according to different contactless power transmission system design requirements, respectively, from the aspects of the circuit composition, iron core structure, air gap distance, power supply frequency is discussed. Key elements of the loosely coupled transformer coupling coefficient is emphatically analyzed by using finite element analysis method, and three transmitter coil honeycomb structure of loosely coupled transformer excitation are designed, and the effects of structural parameters on the excitation are analyzed by using the simulation analysis of line disk, cylinder and laminated composite excitation. It is important reference and guidance significance that the design of contactless power transfer device and the research the structure of the combination loosely coupled transformer excitation are implemented from the theory and practice results in this paper.