The Radiated Characteristics Of Pantograph Arcing In High-speed Railway

The electromagnetic environment of high-speed train becomes very complex.It is important to analyze the characteristics of electromagnetic disturbance sources in order to improve the electromagnetic compatibility(EMC).Pantograph arcing is one of the most important disturbance sources in high-speed railway which leads to many EMC problems.The disturbance generated by pantograph arcing has a wide frequency range.The radiation fields can couple into the communication system on-board and power supply system,and then interfer sensitive equipment.Since the source is related with train speed and environment,it is difficult to analyze the radiation characteristics of pantograph arcing by measurement on-site.In this paper,the methods of computer simulation and experimental platform measurement are utilized to investigate the radiation characteristics of pantograph arcing in high-speed railway.Firstly,based on the generation mechanism,an equivalent circuit model of pantograph arcing is established to analyze the discharge voltage and current in both the normal condition and the catenary covered by ice layer.Secondly,by the analysis of the whole process of the pantograph offline,an occurrence model is established to analyze the law that pantograph arcing takes places during the train running in different speeds.Thirdly,an experimental platform is established to simulate the pantograph arcing phenomena under different train speeds.Fourthly,according to the characteristics of pantograph arcing,a pulse-reference measurement method is proposed,which uses a periodic non-modulated pulse signal as the reference source to measure the total radiated power of arcing in reverberation chamber.The reference pulse width should less than 2.5 times the time constant of the chamber.Finally,based on the experimental platform and electromagnetic filed numerical simulation,the radiation fields of pantograph arcing in high-speed railway are calculated.Using this method,the attenuation characteristic of pantograph arcing are analyzed.Besides,a method to calculate the coupling power from pantograph arcing to antenna on the train roof is presented.The main innovations of this paper are as follows:(1)For the first time,the voltage and current characteristics of pantograph arcing caused by ice on catenary are analyzed,which provide a theoretical reference for the research of the disturbance of pantograph arcing caused by ice disaster.(2)With scale model theory,an experimental platform is designed and established,which can simulate the pantograph arcing at different train speeds in high-speed railway and continuously produce stable arcs for 2 hours.It provides an experimental environment for studying the radiation characteristics of pantograph arcing.(3)A measurement method named pulse-reference is proposed to measure the total radiated power of periodic short pulse signals in reverberation chamber.This provides an effective means for studying the radiation characteristics of pantograph arcing in laboratory.(4)A new method for calculating the radiation field of pantograph arcing is proposed.The method combines experimental platform measurement and numerical simulation,which solves the problem of arcing source remodeling in simulation,and provides a method for calculating the radiation field generated by pantograph arcing and forecasting the radiation disturbance to communication system on-board.These results have certain theoretical and guiding significance for improving the EMC of train.Specifically,the equivalent circuit model and the occurrence model can effectively analyze the voltage and current characteristics of pantograph arcing and present the law of arcing occurrence when train running in different speeds;the experimental platform can be effectively applied to the research on the radiation characteristics of pantograph arcing in different train speeds;the method to calculate the radiation field of pantograph arcing and the radiated disturbance to communication system on-board can provide a reference scheme for arrangement of sensitive equipment and improving the EMC.