Study on Power Transformer Fault Risk Assessment Method

Based on more than three hundred transformer accidents and some statistics data related, this paper manages to draw a standard classification table of transformer failure. 5 degrees of failure possibilities are classified in the paper: extremely high, high, general, low, extremely low. Besides, 4 major factors that affects risk of transformer failure severity are studied: direct lossmonitoring levelmaintenance cost and maintenance period. Also, failure severity of each risk source are classified into 5 levels: not serious, mild, ordinary, less serious, and serious, and Extensional Analytic Hierarchy Process (EAHP) and Extensional Project Appraisal Methods are used to evaluate the severity of risk of transformer failures. Last but not least, risk matrix has been built and divided into four parts: high risk area, critical risk area, medium risk area and low risk area. On that top, some maintenance strategies are proposed accordingly.