TY - JOUR AB - Purpose– The purpose of this paper is to introduce the realizing process of the fuzzy logical reasoning method in relation to the insulation detection of insulator strings, especially about the establishment of the fuzzy relation matrix.Design/methodology/approach– Utilizing fuzzy logical reasoning method, the online fault diagnosis of the transmission line insulator strings can be realized efficiently, although the insulation status of the insulator strings is influenced by many factors and the relation between the measured electric parameters about the insulator with the degree of the deterioration is ambiguous.Findings– Utilizing the pattern recognition method to build the fuzzy relation matrix after choosing the probability of the corona current, the root‐mean‐square value and the peak value and the pulse frequency of the leakage current as the fuzzy operating input variables, using the fuzzy reasoning method to estimate the insulation status proves to be a practical approach.Practical implications– The experiments verify the correctness of this method by simulating work conditions of insulator strings on an 110 kV transmission line.Originality/value– This paper proves that using the fuzzy reasoning method to estimate the insulation status of the online insulator strings is a practical approach. The results of the laboratory and the field tests verify the correctness of this approach and the validity of the identification method to build the fuzzy relation matrix. VL - 38 IS - 10 SN - 0368-492X DO - 10.1108/03684920910994259 UR - https://doi.org/10.1108/03684920910994259 AU - Xu Xiaoning AU - Nie Yixiong AU - Peng Xiangang ED - Mian‐yun Chen ED - Yi Lin ED - Hejing Xiong PY - 2009 Y1 - 2009/01/01 TI - Research on insulation detection of insulator strings with fuzzy logical reasoning method T2 - Kybernetes PB - Emerald Group Publishing Limited SP - 1747 EP - 1753 Y2 - 2024/03/29 ER -