利用分块模型的接地网撕裂法故障诊断  

Splitting Method for Grounding Grids Corrosion Diagnosis Using a Block Dividing Approach

作　　者：倪云峰[1] 刘健[1,2] 王树奇[1] 李腾[1] 李志忠[2] 王森[2] 

机构地区：[1]西安科技大学电气工程学院,西安710054 [2]陕西电力科学研究院,西安710054

出　　处：《高电压技术》2011年第9期2250-2260,共11页High Voltage Engineering

基　　金：新世纪优秀人才支持计划(NCET050875);陕西省教育厅专项科研计划(09JK588)~~

摘　　要：为了便于接地网故障诊断,通常对大规模的接地网采用电路网络理论中的撕裂法进行分解,从而将大规模的接地网撕裂分解成若干个小规模子网络分别诊断,以提高诊断效率。然而传统的撕裂方法会对撕裂边界的接地网支路的故障诊断可测性产生影响。因此分析了传统撕裂法对接地网故障诊断可测性的影响原因,提出了一种基于分块模型理论的分块撕裂故障诊断方法,从而避免了传统撕裂方法对接地网诊断时的可测性影响。首先定义了块及其原形、不确定支路组及其原形等概念,在此基础上,提出了一种接地网分块撕裂的基本原则和分块故障诊断方法。在各个块中,基于面向各个节点分区的测试数据,采用线性最小二乘法求解与各块相关的本征支路电阻,确定各块中的明晰支路电阻,对于不确定支路还可采用二分法求出不确定支路电阻的取值范围。提出的方法将接地网拆分成若干个小规模的子网络进行求解,不仅可以提高计算效率,还可减少量测误差对测试结果的交叉干扰影响,且避免了以往求解本征支路电阻的非线性迭代过程。在陕西渭南东330 kV变电站的一个38条支路的实验接地网上进行了实验验证,结果表明所建议方法是可行的,能够有效减少测试工作量,提高故障诊断效率。To benefit the corrosion diagnosis,generally,the spiltting method of circuit theory is used which can divide the larger ground grid into several small scaled sub-grids to diagnosis by several touchable nodes.The testability for branches can be changed,by adopting the traditional splitting method,namely,along with the touchable nodes splitted.First,the influence of testability for braches is analyzed.The concepts of blocks and their prototypes,uncertain-branch groups and their prototypes,projection of blocks and part of touchable nodes are defined.Based on the mode of block,a new approach of grounding grids corrosion diagnosis by blocks is put forward.According to the desired corrosion diagnosis area,the blocks together with their projections and the parts of touchable nodes,which participate in the diagnosis are determined.According to the testing data of the corresponding parts,the resistances of intrinsic branches in a block can be determined by a linear least square method,thereby,the resistances of clear branches in the block can be worked out.The ranges of resistances of uncertain-branches in the block are also evaluated by a dichotomy algorithm.With the proposed approach,a grounding grid can be divided into several small scaled sub-grids.As a result,the efficiency is improved and the cross-interferences are reduced.An experimental grounding grid with thirty-eight branches is used as an example.The results of corrosion diagnosis show that the proposed approaches are feasible and only a few tests are needed to meet the requirements of diagnosing a certain part of the grounding grid,and the efficiency of corrosion diagnosis can be improved rapidly by the method.

关 键 词：接地网 故障诊断 分块诊断 可测性 分区测试 二分法 

分 类 号：TM862[电气工程—高电压与绝缘技术]