两种杆塔接地电阻测量方法的比较

杆塔接地装置接地电阻的大小对整个电力系统的安全运行有很大影响,其主要测量方法有ZC-8接地摇表法和CA6411钳表法。根据两种方法的测量原理对测量误差和操作时所遇问题进行了分析比较,得出,用ZC-8接地摇表法能准确测量出人工接地装置的接地电阻值,可作为防雷接地设计的重要参数,但费时费力,且测量值比整个杆塔接地装置接地电阻真实值偏小;用CA6411钳表法能测量出雷电流整个泄漏电流回路的电阻值,具有一定参考价值,且操作简单、工作效率高,但也受接触电阻、内回路等因素的影响;在实际测量中,应将二者的优缺点进行互补,合理测量。

Analyzing and Comparision of Two Measuring Methods of Grounding Resistance of Tower

The grounding resistance of the tower has considerable influence on the safe operation of the power system,its main measuring methods are using ZC-8 megohmmeter and CA6411 clamp meter.At comparison of errors and problems between two methods it is found that using ZC-8 megohmmeter,we can get the precise grounding resistance value which can be used as animportant parameter for preventing thunder earthing design,but existing some disadvantages such as time and labour consuming,and the measured earthing resistance value relatively smaller than that of the whole earthing devices.Using CA6411 clamp meter,we can get the whole earthing device resistance value which have some reference value with simple operation and high efficiency,but it also effected by some factors such as contact resistance and inner loop etc;during the actual measurement,we should do the measerment work rationally according to the advantages and disadvantages of the two.