Dynamic Wireless Charging Vehicle Detection Technology Based On Magnetic Coupling

Magnetic Coupling Wireless Power Transfer(MC-WPT)can realize the charging function of electric vehicle while driving,and solve the problem of insufficient endurance of electric vehicle.At present,most of the electric vehicles are powered by segmented guideways,which can not only improve the efficiency of energy transmission,but also reduce electromagnetic radiation and ensure personal safety.The power supply mode brings a new problem —— dynamic vehicle detection.In short,the piecewise dynamic power supply system needs to detect the dynamic vehicle in real time and judge whether the dynamic vehicle reaches the charging area of the current short guide in order to achieve the goal of optimizing the energy transmission efficiency,starting the corresponding short guide at the bottom of the electric vehicle in time and avoiding power failure,It is necessary to detect the dynamic vehicle in real time and judge whether the dynamic vehicle reaches the charging area of the current short guideway.Therefore,the detection of dynamic vehicles is an indispensable part of the dynamic power supply system.The difficulty of dynamic vehicle detection is that the speed of vehicle and the number of charged vehicles are uncertain factors,and the system of dynamic vehicle detection is vulnerable to strong magnetic field interference established by high-power energy transmission system.In view of the above difficulties,this paper proposes a dynamic vehicle detection scheme based on the reverse winding figure-eight coil.The detection scheme can eliminate the strong magnetic field interference from the energy transmission system and accurately realize the dynamic vehicle detection function.In addition,the vehicle's ID is transmitted to the rail switching controller through the vehicle detection system.The rail switching controller provides the energy transmission of the corresponding power level for the vehicle according to the vehicle's ID.Combining with the characteristics of MC-WPT system,this paper aims at completing the task of vehicle detection and vehicle's ID detection smoothly under all weather conditions and reducing signal misjudgment.For the vehicle detection system,this paper establishes a multi-coupling model of signal coil and energy coil based on SP resonance compensation network,and uses AC impedance method to analyze the factors affecting the primary side current of the vehicle detection system.The results show that the primary side current of the system will not be affected by the change of no-load or on-load status.At the same time,considering that the strong magnetic field stimulated by the energy transmitting coil will interfere with the reception of the system signal,this paper decides to adopt the reverse winding figure-eight coil to suppress the interference of the energy magnetic field on the signal transmission,and gives its design scheme considering the mutual inductance value and the induced voltage of figure-eight coil.In order to realize the function of dynamic vehicle detection and vehicle's ID detection,the design method and constraints of signal modulation and demodulation circuit based on magnetic coupling technology are given.Finally,this paper establishes the system simulation model with the help of MATLAB/Simulink software platform to verify that the signal transmission function of vehicle detection system is not affected by energy and magnetic field.Based on the MCWPT system with power of 11 KW,an experimental device of vehicle detection system is built to verify the effectiveness of the vehicle detection system under the condition of high power energy transmission.