Research On Simulation And Optimization On Interface A Of Balise System In High Speed Railway

With the leapfrog development of Chinese railway and the acceleration of going-out strategy, more and more attentions have been paid on the safety and reliability of the train control system. As one kind of high-rate data transmission equipment, the conditions of the Balise system are close to the safety and efficiency of the train operation. As the important data transmission interface, the performance of interface A plays an important role in the system.This paper follows the" modeling and validation-simulation analysis-optimization research " technological process. Firstly, modeling and actual verification is the first step to study the problem. Then the influence of lossy medium is analyzed both from qualitative and quantitative aspects. Finally, comprehensive optimization of the system is conducted by electromagnetic field theory formulas. The main researching works are as following:a) Modeling and validation. To meet the electromagnetic property requirements of interface A, the Balise Reference Loop and BTM Antenna models are built in FEKO software. In order to match the tele-powering, input-output and up-link characteristics of the actual Balise, the parameters of the system model are modified. Therefore, as a whole transmission process, the valid range of Balise and BTM are defined to be analyzed. In order to compare the testing data and simulation data, testing platform of the actual Balise are built to verify the simulation results.b) Simulation analysis. According to the Maxwell formulas, the attenuation characteristics of electromagnetic wave in lossy dielectric and conductors are studied to decide the key parameters. Through theoretical calculation and simulation of train-pass-balise, the influence of each dielectric on interface A performance is analyzed. The variations of the Balise reference loop valid range and BTM valid range are found out by converting magnetic flux into up-link currents at each point position. After quantization of each influence, the method of eliminating the influence shall be analyzed, including routine maintenance, Balise installation improvement and insulating treatment.c) Optimization research. By derivation of the magnetic induction intensity around rectangular antenna, the magnetic flux generated by BTM antenna through the reference loop is calculated. The existence of sidelobe region is analyzed both from qualitative and quantitative views. The variation tendency of the mianlobe and sidelobe is studied when the size of BTM antenna and installation height of Balise are changing. To improve the valid range and restrain the sidelobe transmission, the optimization shall be discussed.