站内轨道电路迂回电路模型分析及案例

Model Analysis and Case Study on the Bypass Route in Station Track Circuit

横向连接在高铁中广泛使用对ZPW-2000系列轨道电路的正常工作造成了潜在威胁,当发生断轨事故时,存在一条回路,使信号依靠该迂回电路向轨道接收端传输信息,导致轨道电路失去断轨检查功能,威胁行车安全。现有的轨道电路仿真和计算并未深入研究,未考虑迂回通道中贯通地线、扼流变压器以及断轨阻抗等完整情况的影响。对此问题进行仿真建模研究对于实现轨道电路的故障诊断,保证列车行车安全具有重要的意义。本文根据四端网理论以及边界条件分析法得到轨道电路断轨状态下的迂回电路模型。经过仿真得到接收端断轨残压与迂回干扰叠加信号,并分析信号载频、道砟电阻、断轨阻抗、轨道电路长度以及迂回长度等因素对接收端干扰的影响,最终计算得到ZPW-2000轨道电路最短迂回电路的相关数值。

The wide use of transverse connection in the high speed railway poses a potential threat to the normal operation of ZPW-2000 track circuit. When a broken rail accident happens, a by-pass loop would form, by which, the signal information could be transmitted to the receiving end of the track. Obviously this may disable the broken rail detection function of the track circuit, and threaten the train operation safety. Currently, no indepth study has been conducted on track circuit simulation and calculation, nor has the effect of complicated conditions, such as run-through earth cable, choke transformer and broken rail impedance in the bypass route been addressed. The modeling and further research on this problem are significant for fault diagnosis of track circuit and the safety of train operation. Based on the four terminal network theory and boundary condition analysis method, this paper establishes the bypass route model under the broken rail state. The mixed signal ineluding broken-rail residual voltage and bypass route interference in the receiving end can be obtained through the simulation. The effects of related factors such as signal carrier frequency, ballast resistance, broken rail impedance, length of track circuit and the bypass length on the interference of receiving end, are also analyzed. Finally, the values about minimum bypass route of the ZPW-2000 track circuit are calcaulated.