Study On Online Monitoring For Contaminated Insulators Of Transmission Line

Flashover accident of transmission line is the second accident of electric power system, just inferior to thunder, but the loss of flashover is decuple of thunder. To guarding against contamination flashover, electrical department set down a scheme to overhaul insulators. However, the scheme spends significant amounts of money on insulator washing and cleaning. Performing the real-time monitor of insulator is a crucial task to solve the safety of transmitting electricity wires. It could heighten the level of preventing contamination flashover, and enable the overhaul of insulators to changing from scheme to state overhaul.The change of insulators elctrometric parameter (leakage current and corona current) has close relation with insulators state and generally reflects the course of contamination flashover. Firstly the mechanism of contamination flashover is researched in the paper. On the basis of studying the parameters that manifest the insulators contamination degree the system monitoring parameters are confirmed.The fuzzy reasoning alarming model application in contamination insulators on-line monitoring system is discussed in this paper. The relationships between corona current, leakage current, environment humidity, environment temperature and level of pollution are studied, then, the problem of fixed value alarming model is analyzed. It is proposed that in order to increase the reliability of prediction, the nonlinear prediction model, which depends on the nonlinear relationships betweenabove factors, is indispensable. Because the nonlinear relationships can hardly be obtained, a nonlinear alanning model based on fuzzy reasoning method is developed in this paper. The fuzzy reasoning alarming has been realized by Visual C++ programming.The results of theoretical analyzing and data verification proved that the fuzzy reasoning alarming method could predict the pollution degree of insulator more accurately. When the degree of contamination was overrun, the system output alarm to inform the staff that the insulators should be cleaned. The problem of missing report and misdeclaration would be solved.