轨道电路是铁路信号系统重要的组成部分,系统的核心器件由微电子电路组成,属于弱电范畴,容易受到外部电磁干扰的影响。地磁暴是一种极端的空间灾害性天气,引起地球的磁场剧烈扰动,地表面产生感应电势ESP(Earth Surface Potentials)。ESP、地面长导体和大地3者构成回路,产生地磁感应电流GIC(Geomagnetically Induced Current)。如果地磁暴侵入轨道电路,GIC威胁轨道电路的正常运行状态。本文探索了地磁暴产生的机理,给出ESP的计算方法;以常用WXJ25型相敏轨道电路接收器为例,分析了地磁暴通过GIC对轨道电路信号传输状态的影响。计算结果表明,如果轨道电路中存在GIC,可能导致WXJ25型相敏轨道电路接收器驱动轨道继电器发生错误动作,是需要高度重视的新问题。
Railway track circuit is an important component of the railway signal system. The core device of the system is mieroelectronic circuit, a light current system that is vulnerable to the external electromagnetic interference. Geomagnetic storm is an extreme weather disaster which causes the severe disturbance of the Earth's magnetic field and results in the Earth Surface Potentials (ESP). ESP and ground together with ground long conductor compose a loop. Consequently, geomagnetically induced currents (GIC) are produced. In the event that geomagnetic storm intrudes into the track circuit, GIC will threaten the normal operation of the track circuit. This paper explores the mechanism that generates geomagnetic storms and finds out the calculation method of ESP. In the case of the commonly used WXJ25 phase-sensitive track circuit receivers, an analysis is performed on the impact on the signal transmission of the track circuit by geomagnetic storms through GIC. The results show that, with the existence of GIC in the track circuit, the WXJ25 phase-sensitive track circuit may cause the track circuit relay to take false actions. This is a problem that requires a high degree of attention.