Magnet Coupled Resonant Automotive Wireless Power Transmission System Research And Design

China already has more than 100 million cars, and 20 million per year to increase rapidly which has brought great challenges in energy supply and environmental protection. Developing electric vehicles, hybrid vehicles and other new energy vehicles has become a consensus, but how to provide simple, fast and secure charging scheme has become a top priority. The rapid development of wireless transmission technology is one of the efficient solutions.This paper will apply magnet coupled resonant wireless power transmission technology to automotive wireless charging, with fixed transmission distance and fixed resonant frequency to improve system efficiency as the goal, research the transmission characteristics of magnet coupled resonant wireless power transmission system and design the wireless power transmission system.Firstly, this article analysis the basic principles of resonant wireless power transmission technology from the angle of electric、magne, explain the importance of high- frequency and compensation capacitor, then build two resonant circuit model system. Improved SSSS four-resonant coil circuit structure is proposed based on analyzing the transmission characteristics and considering automotive wireless charging needs, its transmission characteristic was analyzed and the expression of system efficiency and load power is obtained. Finally obtain the design principles to increase the system efficiency under fixed transmission distance and fixed resonant frequency, also design parameters of the four resonant coils based on the principles.Resonant coils were produced according to the optimal parameters of each resonant coil, completing the building of magnet resonant coupling wireless power transmission test platform and verify the design principles about improving the transmission efficiency under fixed resonant frequency and fixed transmission distance, and research on load power, transmission efficiency, high- frequency excitation effective output power, MOS tube power loss and high- frequency excitation efficiency how to change with transmission distance. When the transmission distance is 20 cm, resonant frequency is 500 KHz, the system, followed the design principles, transmission efficiency is 41.88%, double than the transmission efficiency of the system does not comply with the principle and the transmission efficiency can be increased to 62.6% with standard high- frequency excitation system at the same time. Experiment results show that the high quality factor of the resonant coil and high efficiency, high quality, low output impedance of the high- frequency excitation is the key to the wireless power transmission system to achieve high system efficiency under fixed transmission distance and fixed resonant frequency.