基于蒙特卡罗的接地网故障诊断可测性分析

A Monte-Carlo based on testability analysis of grounding grids corrosion diagnosis

为了分析接地网故障诊断的可测性,提出了一种基于蒙特卡罗的评估方法。在合理范围内,随机设置接地网各条支路的电阻,采用迭代最小二乘法进行故障诊断,计算各条支路诊断结果的平均相对误差和相对标准差,直至达到期望的精度要求。相对标准差小于给定阈值的支路被判定为明晰支路,其余支路被判定为不确定支路。一个60条支路的接地网诊断结果验证了提出方法的可行性,同时该方法表明接地网故障诊断的可测性是可以预计的。可测性研究对于优化测试方案和科学利用诊断结果具有指导意义。

To investigate the testability of grounding grids corrosion diagnosis, a novel approach based on Monte-Carlo method is presented. The resistances of the branches of a grounding grid are set randomly and the diagnosis results are worked out by the iteration least squared approach. The averaged relative diagnosis errors and relative standard deviations are calculated until the desired precision is reached. The branches with their relative standard deviations less than the given threshold are determined as clear branches, and the other ones are uncertain-branches. The diagnosis results of a grounding grid with sixty branches show the feasibility of the proposed approach. It is also shown that the testability of grounding grids corrosion diagnosis can be prior-evaluated and it is of great significance to guide the optimization of testing scheme and scientifically utilize the diagnosis results.