Research And Design Of Wireless Power Transmission System

Wireless power transmission is a new, reliable and safe energy transfer mode, because there is no wire in the transmission process. The devices implanted in human body can be charged through skin by this method. Mobile phones, vacuum cleaners, mobile robots, and other mobile devices are charged by wireless. The high speed trains are also charged by wireless power transmission technology. As the medium range and small power transmission mode, the magnetically coupled resonant is widely concerned. However, there are many problems that need to be solved in wireless Power transmission. The transmission efficiency of the magnetically coupled resonant type wireless power system is very low, because the power transmission circuit's power conversion efficiency is low. When the transmission distance is far, the power consumption is particularly high. At present, the wireless power transmission technology's goal is high transmission efficiency, long distance, small volume and low cost.In order to improve the efficiency of the wireless power transmission system's launch circuit and receive circuit, the single switch tube resonant circuit is used to be transmission circuit, and Buck-Boost converter is used to be receiving circuit. In the basis of anglicizing the single switch tube transmitting circuit's theory model and Buck-Boost converter's working principle, a wireless power transmission system based on magnetically coupled resonant type is designed. The switch tube is controlled by sampling switch tube voltage zero point. The zero voltage conduction is realized through launch circuit's control mode, and the loss is reduced. The receive circuit switch tube is controlled by sampling Buck-Boost converter's input voltage, and make sure that the input voltage is always equal to the proper voltage value. The maximum power tracking is achieved. In addition, the relay coil is used, and the transmission distance is increased. If the relay coil's location is chose appropriate, the transmission distance will be further.In order to verify the feasibility of the system's launch circuit and receive circuit, the experimental instance is designed. The instance parameter: DC input voltage 28±30%V, load resistance 5?, maximum output power 5W. MATLAB/Simulink simulation software is used to simulate the system. And the simulation results show that the launch circuit's control method is able to achieve zero voltage conduction and turn off and the loss is reduced. Experimental platform is set up, and the wireless power transmission device's hardware production and software programming are completed. Debug the system, and the results show that adopting 4 coil structure and 10 cm coil radius, when the received power reaches 5 W, transmission distance can reach 30 cm. The efficiency of transmission circuit is analyzed, and the highest efficiency can reach 58.3%. in the cases of meeting design parameter, single switch tube transmission circuit improve the efficiency of the power transmission circuit, Buck-Boost converter achieve the maximum power tracking, and relay coil increases the system transmission distance.