Research On Resonant Wireless Charging Technology For Electric Vehicle

Electric vehicles rely on electric power, power is a renewable clean energy, relative to oil, low prices. The use of electric vehicles can not only avoid the emission of automobile exhaust gas on the atmospheric environment pollution and harm to the human body, but also can save high fuel costs. Electric vehicle charging is divided into wired and wireless charging, wireless charging and including induction, resonant type, electromagnetic radiation. The magnetically coupled resonant wireless power transmission technology based on near-field coupling and resonance technology, with greater transmission power, transmission distance and so on. MCR-WPT gradually become a hot spot in the field of wireless charging of electric vehicles. In this paper, we mainly focus on the research of the magnetically coupled resonant wireless power transmission technology.First of all, a detailed introduction of the main transmission mode of several radio and understanding of the current status of the study of the magnetically coupled resonant wireless power transmission. The basic principle of the magnetic coupling resonance radio transmission technology is analyzed from three aspects of the coupled mode theory, the circuit theory and the filter theory. Push to export the transport efficiency formula that magnetic coupling resonant wireless energy transmission efficiency and resonant frequency, mutual inductance, coil resistance, load resistance related. It lays a theoretical foundation for the transmission efficiency and the transmission power of the optimized system.Then, respectively, modeling and analysis of the full-bridge inverter circuit and a class E power amplifier circuit, and the simulation and analysis of the full bridge inverter circuit and the half bridge inverter circuit is presented. Based on the comprehensive consideration, the full bridge inverter circuit is selected as the high frequency power source because of its advantage s in the aspects of transmission frequency, transmission voltage and transmission power.Secondly, modeling and analysi ng of the coupling coil, the coil inductance formula, and the transmission characteristics of the system into the efficiency formula is verified by MATLAB simulation. To improve the efficiency of transmission can improve the resonant frequency, mutual inductance, load resistance, reduce the coil resistance.Finally, according to the above analysis theory, a magnetic coupled resonant wireless power transmission system device design. Details of the experimental apparatus function of each module, driver chips, circuit diagram. Including the square wave generating circuit, driver circuit and an RF power source circuit and the transmitting and receiving circuits. After debugging, the system works properly. This device uses flat spiral coil separated by 30 cm 25W light bulb. If continue to improve the input voltage can make the further transmission distanc e, transmission power is bigger. Finally, this system is used in the experiment of frequency characteristic, the experiment of distance characteristic, the influence of the position of the coil on the transmission power, the obstacle and the frequency splitting experiment., and according to the experimental results, the factors that affect the output power are analyzed.