变电所附近地下构筑物对接地电阻测量的影响

Influence of Neighboring Underground Metal Object on Measurement of Substation Grounding Resistance

分析了变电所附近地下金属物体对接地电阻测量结果的影响。如果在测量路径下存在地下金属构筑物,则会导致在视在接地电阻曲线上出现平坦段。该平坦段可能会被误认为对应于真实接地电阻的补偿点位置,导致测量结果出现巨大误差。接地网附近与之不相连的地下金属构筑物对接地电阻的影响很小。如果要利用地下构筑物来降低主接地网的接地电阻,最有效的办法就是将二者连起来。

The in fluence of underground metal object on the measured results of grounding resista nce is analyzed.If there is a underground metal object in the measuring route,i t would lead to a flat region on the apparent grounding resistance curve.This fl at region would be misidentified as the compensation point of potential electrod e corresponding to the actual grounding resistance of substation,and bring huge error.The neighboring underground metal object has small influence on the value of substation’s grounding resistance.If we wish to utilize this underground me tal object to decrease the grounding resistance of substation,the effective meth od is to connect this metal object with the grounding system.