接地网故障诊断可测性指标体系的分析及应用

Analysis and Application on a Family of Testability Indexes for Grounding Grids Corrosion Diagnosis

定义了接地网故障诊断的4类可测性指标即结构可测性、测试可测性、状态可测性和干扰可测性,采用不确定度反映支路和接地网的不确定程度。对于结构可测性、测试可测性和状态可测性分析,采用不确定支路个数反映接地网可测性高低。采用测试明晰支路的平均不确定度反映综合干扰对接地网故障诊断结果的影响程度。提出了基于Monte-Carlo方法的结构可测性、测试可测性和干扰可测性分析方法。对一个具有60支路的接地网进行了结构可测性、测试可测性和干扰可测性分析,结果表明:提出的方法是可行的并且对于优化测试方案和科学利用诊断结果具有指导意义。

Four testability indexes of grounding grids corrosion diagnosis are defined, such as the structural testability, the measurement testability, the state testability and the disturbance testability. The uncertain degree is described by the index of uncertainty degree. The number of uncertain branches is used to compare the testability level of a grounding grid in structural testability, the measurement testability and the state testability analysis. The averaged value of uncertain degree of all measurement clear branches is used as an index to reflect the extent of disturbance influence on the results of grounding grid corrosion diagnosis. Based on the approach of Monte-Carlo, evaluation of the structural testability, the measurement testability and the disturbance testability are presented respectively. A grounding grid with sixty branches is used as a study example. The result shows that the proposed approaches are feasible and helpful for choosing testing schemes and scientifically utilizing the diagnosis results.