Research On Adjacent Crosstalk Based On ZPW-2000 Track Circuit Used In Stations And Intervals

The track circuit is an important part of train operation control system.The reliability of the information transmitted by the track circuit directly affects the safety and efficiency of the train operation.ZPW-2000 jointless track circuit realizes signal isolation of the adjacent sections and reliable transmission of signals in this section through tuning area.The adjacent section interference will be generated,when the tuning area fails,which is not conducive to the safe and reliable operation of the train.With the rapid development of the railway,the multi-line parallel track circuit has appeared.When ZPW-2000 series integrated track circuits are used in stations and intervals,for the station track and the busy section of the intervals in some lines,when the jointless track circuit in the same direction in parallel occurs,it is likely that the on-board equipment will receive the coupling interference signals of the same carrier frequency from adjacent lines,which will affect the accuracy of signal demodulation and endanger the driving safety.Based on this,the interference problem of the adjacent section caused by the tuning area fault and the adjacent crosstalk problem caused by the inductive coupling,capacitive coupling,ballast resistance leakage conduction coupling,and space electromagnetic interference are respectively studied.The research is mainly carried out by establishing a six-port network model and the finite element model of the track circuit.The main contents are as follows:Firstly,the causes and interference mechanism of adjacent section interference / adjacent crosstalk are studied,on the basis of studying the structure and working principle of the ZPW-2000 series integrated track circuits.Based on the transmission line theory and considering the impact of rail-to-ground leakage and other factors,the six-port network models of ZPW-2000 jointless track circuit and ZPW-2000 integrated station track circuit and adjacent section interference of ZPW-2000 jointless track circuit model are established.Secondly,according to the established six-port network model of ZPW-2000 series integrated track circuit,the six-port network models of double-lines ZPW-2000 jointless track circuit and double-lines ZPW-2000 integrated station track circuit are established,on the basis of establishing the rail model,the compensation capacitor model,the sending end model and the receiving end model of double-lines track circuit.Based on the importance of rail mutual impedance and other parameters in the process of model establishing,the simulation analysis of their changes is carried out.Finally,the correctness of the single-line track circuit model and the double-lines track circuit model are verified based on the established models.The models are used to simulate the induced voltage of the adjacent section interference in TCR and the short-circuit current when adjacent section interference / adjacent crosstalk occurs.In addition,through the finite element model of the track circuit,the problem of adjacent crosstalk caused by space electromagnetic interference is simulated and analyzed,and the correctness of the finite element model is verified by combining with the theory of electromagnetic field.The results show that the models of the track circuit established in this thesis are correct,and they can be used for the study of adjacent section interference / adjacent crosstalk.Factors such as the mutual impedance of the rail and the signal carrier frequency will affect the magnitude of the adjacent crosstalk.Only when the polar impedance tuning unit to the frequency of this section fails,the voltage amplitude of the adjacent section interference components will be large.If the compensation capacitors which are close to the receiving end in this section and adjacent section are all faulty,the train may still operate normally.The higher the signal carrier frequency is,the weaker the magnetic field intensity will be.If the signal current transmitted on the adjacent rails of the two lines are in the same direction,the adjacent crosstalk will be larger during the train operation.If the signal current transmitted on the adjacent rails of the two lines are reversed,the coupling coefficient will decrease with the increase of the carrier frequency,when the jointless track circuits in the same direction are parallel.The research can provide theoretical support for the study of adjacent section interference / adjacent crosstalk.