基于模糊层次分析法的接地网状态评估研究

The Study of Evaluation for Grounding Grid Using Fuzzy Analytic Hierarchy Process

评价接地网安全性的特征参量包括接地阻抗、导通电阻、跨步电压和接触电压等,但单一的指标并不能表现接地网状态的好坏,需要综合考虑各个参量。本文利用模糊层次分析法建立了接地网层次分析模型,将变电站的初始特征参量和规定的特征参量阈值进行组合,构成层次分析模型最低层的五个方案,按照禁忌搜索算法逐次迭代找出五个成对矩阵内的最优元素组合,正规化变换后求出成对矩阵最大特征值的特征向量,即权重值。最后将目前变电站实测的特性参量值按照二维线性函数运算重新确定比较矩阵内的元素值,并得出接地网状态评估结果。结合实例分析,验证了该评估方法的正确性和可行性。

The characteristic parameters of the grounding grid include resistance of grounding grid,connective resistance,step voltage and touch voltage etc.For evaluating the security,the method that compares of the single characteristic parameter and the prescriptive threshold value is employed.But now there is no intact method that can be used for evaluating the status of current grounding grid.The model of grounding grid analytic hierarchy is founded based on fuzzy analytic hierarchy process（FAHP）,combining the initial parameters with the propositional parameters of excess in the standard make up of the five projects in the bottom of FAHP model.Later,the excellent element combination of the double matrix are founding using the iterative of the tabu search,the eigenvectors of the biggest eigenvalue,as well as ratio coefficient,are calculated after the normal change.Finally,the new elements of the double matrix are calculated based the planar linear function adopting the current measurement parameters of the substation grounding grid,and gain the result of the evaluation.The analytic results of the actual example show the method of the evaluation is accurate and feasible.