接触网支柱接地状态对支柱二次保护设备的影响试验研究

Experimental Study on the Influence of Grounding State of OCS Pillar on Secondary Protection Equipment

接触网供电线的上网隔离开关发生接地短路常造成牵引变电所及分区亭二次系统故障,通过试验研究接触网支柱接地回流状态对支柱上的二次保护设备的影响。制定接触网上网隔离开关短路试验方案,试验得到接触网支柱接地回流通畅与不畅两种状态下短路对支柱二次系统的影响,测得牵引变电所二次系统各点的电压以及通过不同路径的回流电流。通过对试验结果进行分析,发现当回流路径通畅时,支柱接地极电压升差仅为35 V,不会造成二次系统损坏;回流路径断开时,短路电流在支柱基础上产生高压,暂态电压峰值达到6400 V,导致将二次设备击穿。研究发现,加热管、三孔插座和SPD是二次保护设备绝缘薄弱环节,击穿电压在2200 V左右,SPD在该情况下不能起到保护作用。

The grounding short circuit of the disconnector of catenary power supply line often causes the secondary system fault of traction substation and partition kiosk.Therefore,this paper studies the influence of the grounding return state of OCS pillar on the secondary protection equipment through experiments.The short-circuit test scheme of OCS on-line disconnector is formulated.The influences of short-circuit on the secondary system of OCS under two states of unobstructed and blocked grounding return current are obtained.The voltage at each point of the secondary system of traction substation and the return current through different paths are measured.The analysis of test results finds that when the return path is smooth,the voltage rise difference of the pillar grounding electrode is only about 35 V,which will not cause damage to the secondary system;when the return path is disconnected,the short-circuit current will generate high voltage on the foundation of the pillar,and the peak value of the transient voltage will reach up to 6400 V,which will lead to the breakdown of the secondary equipment.It is found that the heating pipe,three hole socket and SPD are the weak points of the secondary protection equipment insulation,the breakdown voltage is about 2200 V,and SPD fails to play a protective role in this case.