Research On Packet Loss Of EMC Interference In Network Control System Of High Speed EMU

Train network control system is a data communication system which is control oriented and connected to vehicle equipment.It is the core equipment.With the rapid development and popularization of microprocessor technology and field bus technology,train control system has changed from direct digital control system to a Web-based distributed control system,which greatly reduces the interconnection between devices.The bus standard often used for trains was TCN,CAN,Lonworks,WorldFIP,etc.Especially TCN standard is most widely used standard in the world.Therefore,this paper mainly focuses on the EMU network control system based on TCN standard.The increase of vehicle equipment worsens electromagnetic environment of EMU.Interference like electrostatic interference,pulse interference and surge interference,can invade network control system equipment and circuit through various coupling ways,interfere with train network communication and cause TCN packet loss.If the control instructions of key equipment are lost,incalculable damage will be caused to the safe operation of EMU.If the information of equipment failure is lost,staff will fail to make timely emergency response,therefore the safe operation of EMU cannot be guaranteed.Research on train network control technology in our country started later than other countries,the study on TCN standard protocol has been in the stage of theoretical research.At present,although our country has already mastered the technique of independence development of train network control,research on the influence of electromagnetic interference on train network control system is still in the blank stage.Therefore,this paper builds an EMU network control experiment platform in the laboratory according to the CRH5 EMU network topology(WTB+MVB).The platform mainly consists of the subsystems in two head cars,Mc1/Mc2.Typical electrostatic interference and pulse interference are added to the EMU network control experiment platform through electrostatic discharge generator and pulse generator.And then the number of lost packet under different interference voltage is counted through TCN network analyzer which can record real-time bus data.Finally,under the relationship between packet loss rate and different interference or different interference voltage is obtained,and then packet loss rate prediction model based on interference is built through statistical tool.The research method in this paper can be used in the study of packet loss based on interference on not only TCN fieldbus but also other fieldbus.