变电站接地体材料对杂散电流的响应

Influence of Stray Current on Grounding Grid Materials at Substation

为了研究杂散电流对变电站接地体材料的影响,设计了镀锌钢、钢和铜三种材料在变电站回填土中的电解腐蚀试验。结果表明:杂散电流会加速金属接地网的腐蚀;在盐渍化严重的土壤,镀锌钢和钢受到自然环境腐蚀和杂散电流电解腐蚀共同作用。金属的腐蚀质量损失量与通过金属体电量成正比;而实际试验中由于环境影响和材料自身原因试验测试值与理论值有较大误差;铜试样具有较强的抵挡自然腐蚀能力,质量损失主要为杂散电流电解腐蚀。研究结果可为变电站接地网设计提供有益的参考。

In order to study the influence of stray current on the grounding material of substation,a series of stray current corrosion test on galvanized steel,steel and copper in the backfill of substation was carried. The re- sults show that stray current accelerates corrosion of metal grounding grid. In salinized soil,galvanized steel and steel are affected by natural environment corrosion and stray current electrolysis corrosion. The loss of corrosion mass of metal is proportional to the quantity of electricity passing through the metal. Because the environmental in- fluence and the material's own reason,there is a big error between the test value and the theoretical value. Copper samples have strong resistance to natural corrosion,and it mass loss is mainly stray current electrolytic corrosion. Study can provide a useful reference for substation grounding grid design.