Simulation and Analysis of the Impact of EMI from Urban Railway Traction System on Axle Counter

According to the configuration characteristics of axle counter cables in urban (suburban) railways and based on electromagnetic induction theory, the calculation of mutual inductance coefficient between traction current in rail and axle counter cable core is completed, and the simulation method of overcurrent in train traction transient process (e.g., circuit breaker switching) and the calculation method of induced voltage generated on axle counter cable core is proposed. Firstly, selecting a typical axle counter and its configuration, we analyze its working principle and interfered mechanism and confirm that the interference source is rail traction current, which forms induced burst voltage on axle counter cable through spatial magnetic coupling. Based on the MATLAB platform, the transient overcurrent waveform and value are simulated and verified. Further, according to the laying conditions and engineering parameters of the axle counter cable in the urban railway, the transient induced voltage generated by overcurrent on the axle counter cable core is simulated and calculated. Finally, referring to the interference case, the application and verification of the above method are completed. The conclusion shows that under certain conditions, the traction strong electric interference of the urban railway will exceed the signal voltage threshold of the axle counter, leading to the counting error of the axle number.