| As a green energy vehicle, electric vehicle has got high attention by the countries all over the world in recent years. But its further application has been restricted by the problems of battery life and charging because of the limited battery technology. Under this background, the wireless power supply technology for electric vehicle based on ICPT has got attentions of many universities and research institutions in recent years. The main principle of ICPT is that primary energy coil buried underground provides the energy for electric vehicle directly, this technology can improve the battery life of electric vehicle greatly, and decrease the needing of batteries. In order to improve of the efficiency of the system, the primary energy emit coil is always designed as short section type, and only the section under the electric vehicle is selected and powered, this requires the system can sense the position of the electric vehicle and then choose the corresponding coil to transfer electric energy.Aiming at implement the wireless power transfer system for electric vehicle, this paper has done jobs in two aspects: detecting of vehicle position and switching of the rail, the detail work is as follows:This paper firstly explains the current research status and the structure of wireless power transfer system for moving electric vehicle, and presented the require analysis. Then presented a dual-coil position detect method and the corresponding coil switch control method based on the analysis of current methods.This paper proved the reliability of dual-coil detect system by theoretical deduce and computer simulation, and designed the position detection device in three aspects: the signal emit circuit, the emit and receive coil and the signal processing circuit. First developed a kind of time-fixed compensation method for the soft-switching circuit of signal emitter, which can improve the working frequency range and avoid the influence of frequency change which is a character of traditional C-R compensation circuit. For the designing of signal coil, this paper has given a proper size design based on the Ansys Maxwell and Matlab. The signal-processing circuit is implemented based on the MCU that contains A/D converter inside, which reduces the system cost and also incases the reliability and maintainability of the system.In aspects of rail switch control, this paper presented a simplified type mixed distribution pattern. Based on it, the paper also designed control software to identify the driving direction and control the state of the primary energy coil, and also explained the main part of the switch control circuit.Finally, the paper set up the circuit of position detection and switch control and presented the control program, which verified the validity of the above analysis and design. And the system alignment result also verified the effectiveness of the proposed place detection and rail switch control. |
