Affiliations: [a] School of electrical engineering, Xi'an Jiaotong
University, Xi'an 710049, China
Correspondence:
[*]
Corresponding author: Liqiang Liu, School of electrical
engineering, Xi'an Jiaotong University, 28 West Xianning Road, Xi'an 710049,
China. E-mail: llqiang@imut.edu.cn
Abstract: In China, the serious accidents due to severe corrosion of
substation's grounding grid often take place. To better analyze results of
corrosion diagnosis for grounding grids, a novel approach to creditability
analysis by means of testability matrix factorization was presented. A new
testability matrix was derived, which has only to do with topological structure
and test information without any partial derivative operation, and then
nonlinear diagnostic equations were established. The branch ambiguity groups
and the set of surely testable branches were obtained through the testability
matrix by Gauss-Jordan elimination method. The example of simulation shows that
the results of the surely testable components are changeless in different
diagnosis under fully tested conditions. It points out that misdiagnosis is
inevitably due to the existence of ambiguity groups.
