Fundamental Research On Measuring Earth Resistance By Adopting Multi-Current Auxiliary Electrodes

The grounding system is very important, it can protect the human bodies and equipments efficiently. Measuring the resistance of the grounding system precisely, either to the human life or to the economy, has great significance. A new method of grounding resistance measurement―multi-current auxiliary electrode method that is quite different from traditional three-electrode method is presented. Multi-current auxiliary electrode method that means arranging many current electrodes(C) around the grid (E) can measure the grid grounding resistance precisely and effectively and primarily conveniently. In chapter 1, first of all, the basic concept and significance about grounding are given, then this chapter analyses developing status of grounding resistance measurement and educes significance of this research from existent problem at present. In chapter 2,the fundamental principium of measuring grounding resistance is analyzed detailedly, further introduces typical measurement methods in the world. In chapter 3, systemic analysis in theory is given about multi-electrode method. From three-electrode method,this chapter educes expressions of spot of zero potential and spot of compensating error when we measure earth resistance in four-electrode method, five-electrode method, six-electrode method, ten-electrode method and random electrodes method, but it finds out their variation rules with increase of current electrode. In chapter 4, on the basis of academic analysis, an integrated experimentation project is designed, then experiments on eight electrodes respectively including hemisphere,ring,reticulation etc,and gains curves of diversified parameters with increase of current electrode, compares them with parameters of hemisphere electrode. In the end, by analyzing experimental results, this article generalizes common rules of earth resistance measurement based on multi-electrode method.