Research On Uplink Electromagnetic Interference Of Train On-board Balise Module

In recent years,with the rapid development of high-speed railway and urban rail transit in China,more and more communication equipment and an increasingly complex electromagnetic environment put forward a more severe test on the reliability of signal transmission in the train vehicle system.Train on-board balise module is one of the core components of the train signal control system.It is responsible for providing the required line and position information for the train.After the on-board balise is subjected to electromagnetic interference,it will directly affect the driving efficiency and passenger riding experience.As an important part of the on-board balise,the on-board BTM antenna is directly exposed to the complex environment under the vehicle,which is easier to receive the radiated interference signal sent by the vehicle system,resulting in the disturbance of the on-board balise module.The formation of a complex electromagnetic environment under the vehicle is closely related to the fact that the high-power equipment of the vehicle is mainly placed at the bottom of the train,and the traction system and the grounding system under the same vehicle form a traction return path.The recent interference problems of on-board balise are mostly caused by the interference signal generated by the train traction system coupled to the BTM antenna.However,in the current research on the uplink interference of on-board balise module,no simulation model can predict the interference of on-board balise module caused by the traction system,It is impossible to further analyze and explore the interference suppression method of the on-board balise module based on the model.Therefore,it is necessary to further study the uplink electromagnetic interference of train on-board balise modules based on the interference problem of on-board balise modules in existing vehicles.Aiming at the problem of uplink interference of on-board balise module caused by traction system,this paper first analyzes the working principle and interference mechanism of urban rail train balise system,combs the potential interference sources of on-board balise module,and obtains that the main interference source is the radiation interference generated by traction system,and the main receiving carrier of interference signal is on-board BTM antenna.By analyzing the generation mechanism of interference source and complete interference transmission path of urban rail train traction system,the simulation and prediction model of uplink electromagnetic interference of on-board balise module is established,the interference signal of on-board BTM antenna port is obtained,and the interference of on-board balise module uplink is evaluated.Finally,the simulation results are compared with the existing vehicle test results to verify the accuracy of the simulation prediction model.Secondly,based on the simulation and prediction model of uplink electromagnetic interference of on-board balise module,the interference law of vehicle balise module is further analyzed,the distribution characteristics of interference current are explored,and the interference size of vehicle BTM antenna interference caused by different interference circuits is quantitatively analyzed,It is clear that the main radiation interference circuits are: Traction converter→input side cable of traction converter→traction transformer→transformer primary grounding→grounding system→traction converter grounding wire→traction converter shell→traction converter.Finally,based on the interference law of the uplink of the vehicle balise module,a shielding structure that can be used to suppress the interference of the vehicle BTM antenna is designed.The shielding effect of the shielding structure on the interference signal and the normal communication performance of the BTM antenna is analyzed,the optimal shielding structure parameters and installation position are obtained,and the effectiveness of the shielding structure is verified by the actual line where the vehicle balise module is disturbed.The interference control strategy proposed in this paper provides an effective solution to the practical problem of the interference of the on-board balise module of the train and improves the anti-interference ability of the uplink of the on-board balise module during the operation of the train.