Study On Interference Upon Track-side Signaling From Electrified Railway Under High Speed And Heavy Haul Conditions

Microelectronic technology has been increasingly applied in signaling control system of high speed and heavy haul railways, which is essentially sensitive to electromagnetic interference (EMI) caused by electrified railway. EMI may lead to signal malfunction that will consequently disrupt railway operation even threaten the safety. Under this background, featuring the influence of strong EMI, e.g. conductive interference and transient, upon track circuit and signal cable, interference mechanism and corresponding preventive measures are discussed in this thesis. Major work focuses the following four aspects.At first, considering some key influential factors such as ground wire, bridge section and signal cables, a novel model was established to analyze the distribution of traction current by a group of node-voltage equations. After interference values were analyzed and calculated theoretically between single grounding and double grounding, the result that single grounding is better than the latter was verified in indoor simulation test.Secondly, the characteristics of traction current and its impact on track circuit were studied; then the solution of station track circuit for high speed and heavy haul railways was designed and implemented, which can meet the requirement under high traction current interference. In addition, according to distribution features of signal and harmonics, Zoom FFT algorithm was adopted in the track circuit receiver, and feature-based method was discussed to identify the polluted signal spectrum.Thirdly, transient phenomena related with traction current were illustrated on two cases, one is the damage of insulation joint in high speed railway station, the other is the burning of signal cable in bridge section of heavy haul railway. In accordance with the actual operation, the simulation test was devised to acquire enough and synchronized voltage and current data, which were analyzed and matched with Cassie and Mayr arc combined model. Further, the high temperature from electric arc was confirmed to be the reason of the phenomena.Finally, concerning synthetically monitoring interference on track-side signaling, the distributed monitoring scheme based on ZigBee wireless sensor network technology was designed; an image mosaic algorithm was implemented to enlarge the target view and range; and a data-based hybrid algorithm was developed on track circuit fault diagnosis to improve its real-time and accuracy.