Study On The Condition-based Maintenance Strategy Of Electrical Equipments

The maintenance strategy of electrical equipments has gradually being changed from Time-based Maintenance (TBM) to Condition-based Maintenance (CBM). Although some effects have been achieved, the CBM strategy of electrical equipments is sticked in academic area in China because of the different understandings of the definition and signification of CBM. Moreover, some integrated discussions and researches of CBM strategy is wanting at the present time. Based on the existing researches, this paper does some systemic research on the key techniques of CBM chiefly.Firstly, this paper generalizes the academic and practical status of domestic and foreign Condition-based Maintenance strategy of electrical equipments. Some mistakes and bugs of present researches are analyzed. The key techniques of CBM are generalized to condition monitoring technique, condition forecasting technique and condition assessment technique. The function of each technique is expatiated, while the connections among CBM, online monitoring and fault diagnosis has been made clear.Security-based and economy-based methods for confirming the time interval of condition monitoring in CBM are given in this paper. Time Serial Analysis Method is used to predict future condition of electrical equipments. Appropriate ARIMA model is constructed to analysis and predict the characteristic parameter time serial which is periodic and trended. The validity of this ARIMA model is approved by predicting the gas-in-oil parameter of an electric transformer. Then, a new condition assessment method based on variable weights analysis is presented. An assessment example is given while a local variable weight function being constructed. Based on this result, some recommendable CBM decision-making values and maintenance operations are listed in this paper. Effects on the reliability of equipments by TBM and CBM strategy are discussed in both ideal and non-ideal cases.At the end of this dissertation, the main results of the research are summarized. And point out the deficiency existed in research process. The further work is submitted as well.