Analysis Of Railway Signal System Electromagnetic Interference From Traction Power Supply System

Along with the continuous application of advanced technology in the railway signal system including computer technology, the microelectronic technology, the networking and the communication technology, the railway signal equipment adopts massively the electron device and the computer interconnection system and ZPW-2000A sector block system as representative modern railway signal system are universalized gradually at the site. Taking the antijamming into account, the above systems are more easily disturbed by the traction power supply system. Therefore, the railway signal system antijamming research have got more and more attention.This article expounds the forming principle of interference signals caused by traction power supply system, analyses the cuase of unwanted signals-the electric by introducing the railway signal system structure and the electric traction power supply system structure, studies the entry mode and inroad way of signals by researching the signal system structure and at the same time calculates inductive coupling, capacitive coupling, unbalanced traction current, harmonic interference and electric spark pulse in high accident frequency signal lines according to actual accidents at site. Secondly harmonic component in overhead catenary brought by chopping and representative harmonic distribution rule are analysed and generalized. By the generalisation, choosing corrct carrier frequency and frequency departure should be considered to be the key principle during the noninsulated track circuit design to raise the anti-jamming capability.On the basis of systematic analysis and field work, three aspects including design calculation, equipment lectotype and electromagnetism compatibility design are brougt forward to enhance the signal system anti-jamming capability. At the same time, project construction measure, operation maintenance at the site and standard specification establishment are proposed to be considered in the solution to disturbance from traction power supply system.