城市地铁、轻轨车辆段内的列车无机车信号显示,因此其轨道电路的功能仅为列车占用检查。由于西安地铁一号线西咸车辆段内电力机车一般为直流牵引,且牵引回流为单条钢轨,50Hz交流连续式轨道电路需加设滤波器防护,滤波器故障不能保证安全,故轨道电路须采用单轨条回流方式的50Hz相敏轨道电路。现将单轨条式50Hz相敏轨道电 City subway, light rail car train without locomotive signal display, so its track circuit function is only train occupancy check. As the Xi-Xian Metro Line Xi Xian depot electric locomotive is generally DC traction, and the traction return to a single rail, 50Hz AC continuous track circuit to be added filter protection, filter failure can not be guaranteed, so the track circuit to be used Monorail reflux 50Hz phase sensitive track circuit. Now monorail 50Hz phase sensitive track electricity