| The paper focuses on the state assessment and prediction of insulators' contaminative system, the purpose is to study a suitable algorithm for making sure the contamination degree of insulators. Cooperated with Bishan Power Supply Bureau, the monitoring system was developed, insulators state assessment and alarm system was developed as well based on insulators state assessment algorithm. Monitoring instruments were installed on 110kV line in four different sites in Bishan. Since March 21,2007, a large number of data was received and processed. To further determine the pollution level of insulators, the modern power spectrum method is used to analyze the pulses signal.The main contents and outcomes are listed as follows:(1)Preceding researchers' achievements for the contamination flashover are summarized, the physical model of contamination insulator flashover is introduced and its mechanism is analyzed. A receiving system was developed with LabVIEW based on series port, and the wireless communication module was designed.(2)The assessment method of insulator contamination level based on multilevel fuzzy comprehensive assessment was put forward. Weight of inherent parameters and environmental factors was determined by analytic hierarchy process, it can be adjusted by variable weights formula. Then its membership degree function was defined by fuzzy mathematics based on original achievements. Then we developed the assessment and prediction system. The validity of this method is proved by laboratory and field data.(3)Power spectrum density (PSD) of ultra-violet discharge pulses 110KV polluted insulators was roughly analyzed, applying Burg algorithm to establish the autoregressive model based on field data, the features were extracted, it is possible to define insulator contamination level. The linear prediction was come true based on autoregressive model, final results indicated that this model had high prediction accuracy.
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