Research On Efficient Calculation Method Of Field-line Coupling In Railway System

The high-speed railway contains a large number of various types of cables,which are often connected with the train control system and are important to ensure the safety of the train operation.In addition,the outdoor environment also contains the rail as the signal transmission carrier of the track circuit.Both of them are extremely vulnerable to electromagnetic interference,which threatens the safety of the train operation.Based on the practical project of Hebei Key Laboratory of Electromagnetic Environmental Effects and Information Processing,this paper studies the electromagnetic pulse coupling problem of transmission lines in two typical scenes,the cable inside the compartment and the rail outside the compartment,in the high-speed railway system.The main work is as follows:(1)Study on parallel FDTD calculation method based on Hadoop.Aiming at the low efficiency of the serial FDTD algorithm in processing large-scale objects,research Hadoop and Spark computing principles,and build Hadoop large-scale computing clusters.Study the principle of parallel FDTD,and propose an integrated parallel FDTD algorithm based on Hadoop including target model meshing,which solves the problem of accurately and efficiently solving the electromagnetic field of electrically large-scale targets,and provides calculations for subsequent research on field-line coupling problems platform.(2)Study on the electromagnetic pulse coupling law of shielded cables in highspeed rail cars.The dual transmission line model of shielded cables in the carriage is studied,and a new field-circuit hybrid algorithm combining the parallel FDTD method and the transmission line equation under the Hadoop platform is proposed.The correctness and efficiency of the algorithm are verified through a calculation example,and the solution is solved Efficient calculation of the transient response of high-speed rail car cables under electromagnetic pulse irradiation.The parallel field-circuit hybrid algorithm is used to analyze the coupling law of the shielded wires in the carriage under different heights,radii and other influencing factors,which can provide references for reasonable wiring in the carriage.(3)Study on electromagnetic pulse coupling effect of long rail with compensation capacitor.The rail cross-section structure is irregular,and it is difficult to directly model.Using the irregular shape transmission line equivalent method and the feature selection verification method,an equivalent model of a long rail transmission line with compensation capacitors is established.Based on this model and transmission line theory,a long rail-compensation capacitor integrated field-line coupling calculation method is proposed,which realizes the integrated calculation of rail-compensation capacitor.Finally,the method is used to analyze the coupling law of rails of different lengths under plane wave irradiation.The results show that as the length of the rails increases,the peak coupling current is saturated.