变电站电缆沟内接地导体对腐蚀诊断的影响.docxVIP

DOI: 10.13336/j.1003-6520.hve.2014.02.024变电站电缆沟内接地导体对腐蚀诊断的影响刘渝根 1，成文杰 2（1.重庆大学输配电装备及系统安全与新技术国家重点实验室，重庆 400030； 2.石家庄市电力公司，石家庄 050051）摘 要：实际地网腐蚀诊断中，难以判断变电站电缆沟接地导体是否与地网相连，或两者相连时具体节点位置不 明确，因此，常常忽略变电站电缆沟内导体的影响。通过地网腐蚀诊断软件仿真分析电缆沟导体位置、腐蚀程度、 数量以及跨距对腐蚀诊断的影响，并与不考虑电缆沟导体时的诊断结果进行对比。结果表明：当电缆沟导体与主 网连接，不论跨度大小，当其与腐蚀支路间距离(D)不大于主网单根支路长度的 3 倍时，电缆沟导体距腐蚀支路越 近，数量越多，腐蚀支路诊断准确度越低；电缆沟导体腐蚀越严重，腐蚀支路诊断结果越接近真实情况。增加电 缆沟导体附近增大倍数不明显的支路作为开挖对象，可以提高诊断的准确率。 关键词：变电站；接地网；电缆沟；拓扑结构；腐蚀诊断；准确度Influence of Grounding Conductor in Cable Duct on the Corrosion Diagnosis in the SubstationLIU Yugen1, CHENG Wenjie2(1.State Key Laboratory of Power Transmission Equipment System Security and New Technology, Chongqing University， Chongqing 400030, China; 2. Shijiazhuang Power Company, Shijiazhuang 050051, China)Abstract：In corrosion diagnosis of grounding grids, it is hard to figure out whether the grounding conductors of cable duct are connected with grounding grid or not, or to estimate the position where the two are connected, thus the influence of the cable trench conductors is generally ignored. Consequently, to determine the effect of this ignorance, using grounding grid corrosion diagnosis software, we simulated the influence of some parameters of cable trench conductors, i.e., position, corrosion degree, quantity, and span length, on corrosion diagnosis. The results are compared with those of the simula- tions that ignore conductors of cable duct. It is concluded that when cable duct conductors are connected to grounding grid, no matter how far it is between the two, if the distance between the cable duct conductors and a corrosion branch, D, is not more than three times as long as a single branch, the accuracy of corrosion branch diagnosis decreases with the in- crease of the number of cable duct conductors and the decrease of D. Besides, the more corroded cable duct conductors get, the more accurate the diagnosis is. Moreover, the accuracy of diagnosis can be improved effectively by additionally excavating the