| With the popularity of electric vehicles,wireless charging technology is gradually being paid attention to and studied.Electric vehicle wireless charging is divided into two scenarios:parking lot and highway dynamic charging,compared with direct charging,it has the advantages of saving charging piles and reducing charging occupation time,but it is easy to lose power because of parameter offset and occur the phenomenon of unauthorized electric vehicle power theft.Inductor tuning device can adjust the resonant network parameters online,to achieve the purpose of adjusting the working state of the circuit,is an important means to ensure and improve the efficiency of energy transmission of wireless energy transmission system,and can solve the problem of wireless energy encryption transmission through tuning,which has broad application prospects in the field of wireless charging of electric vehicles.The main research content of this article is as follows:1)The working principle and advantages and disadvantages of four kinds of adjustable inductors were analyzed,and the working mode of the traditional core-adjustable adjustable inductor which is suitable for wireless energy transmission of electric vehicles is analyzed in detail,and the causes of large losses of the control circuitand poor working stability were summarized.On this basis,an improved series and parallel permanent magnet bias adjustable inductor was proposed,and the prototype design was completed.Proposed adjustable inductors can improve the inductor adjustment range,regulation efficiency and operating stability by reshaping the magnetic circuit structure.2)Taking the adjustable inductor as the main body,based on the bidirectional adjustment requirement of the inductance tuning device,a control circuit using the V2 prediction deadbeat control method was constructed,and the overall implementation scheme of the inductance tuning device is proposed.Through the finite element analysis software,the regulation efficiency and working stability of the three types of core-adjustable tunable inductors were compared,and the analysis results confirm the superiority of the parallel scheme and the reliability of the design process.The application of the inductance tuning device in the resonant converter was studied by simulation,and the effect of the inductance tuning device on the load power regulation was proved.Finally,the correctness of theoretical analysis and simulation results was verified through prototype production and experimental testing.3)Aiming at the deviation of resonant network parameters caused by the aging of components or manufacturing factors,an adaptive tuning module applied to the receiving end of wireless energy transmission was proposed.Based on the inductance tuning device,the control algorithm of the adaptive tuning module was studied to realize the online tuning of the wireless energy transmission system under different load conditions,and achieve the purpose of the maximum output voltage of the load.The effectiveness of the adaptive tuning module is verified by simulation and experiment.4)In order to prevent the occurrence of electric vehicle stealing by wireless charging,an implementation method of wireless energy encryption transmission is proposed based on the inductance tuning device.Firstly,the frequency sensitivity of wireless energy transmission efficiency under different resonant networks was analyzed,the structure of wireless energy encryption transmission system was proposed,and the frequency hopping working mode of electric vehicle wireless charging highway was summarized.Aiming at the problem of power theft,by analyzing the laws and characteristics of power theft,the standard and control parameter value method for preventing power theft were formulated,and the frequency hopping parameters that meet the requirements of preventing electricity theft were selected for simulation and experiment,and the validity of the parameter value method is verified.the results showed that the power of the unauthorized end is less than 5% of that of the authorized end,and the power of the theft end is less than 20% of that of the authorized end.The research results of this paper can provide certain references and references for the design of new inductor tuning devices and the design of wireless energy encryption transmission systems. |
PDF Full Text Request