The Syntactical Pattern Recognition for the Leakage Current of Transmission-Line Insulators

For the current analytical method of the leakage current on the insulator, the online monitoring system could not be used to accurately judge the contamination severity on the surface of insulators, and a novel method, syntactical pattern recognition, was proposed in this paper. The geometric primitives were extracted by piecewise linearization from the leakage current signals. In accordance with the given grammar, these primitives are constituted into a language recognition unit with the name of finite automaton, where after the finite automaton, the leakage current signals were judged to be the corresponding pattern. The syntactical pattern-recognition module was embed into the “Acqs” software, and a series of experiments for validating this method´s performance were made under the following three different conditions: 1) the leakage current of polluted insulators under the different humidity degrees; 2) the leakage current under the different voltage values with moderate humidity; and 3) the polarity effect. The results showed that the structure information of the leakage current could be roundly obtained by the syntactical pattern-recognition method. Consequently, the surface discharge characteristics of insulators could be deeply grasped and the polarity effect of the leakage current of insulators could be accurately and fully recognized.