A Risk Assessment Method of Power Transformer Based on Three-Parameter Interval Grey Number Decision-Making

In the process of power transformer risk assessment, loss degree index is difficult to accurately quantify due influence uncertain factors, leading deviation judgment. A assessment method based on three-parameter interval grey number decision-making proposed. Firstly, fault probability quantified condition evaluation results. Secondly, considering uncertainty DG output and load, Nataf transform Cholesky decomposition were used eliminate correlation random variables, a three-point estimation combined with DC cut load model was introduced calculate distribution caused by fault. Finally, origin moment each order obtained calculation formula value, through Cornish–Fisher series expanding. The decision distance measure judge grade equipment. results show that proposed fully considers equipment judgment, can realize full use value risk, avoids defects traditional certain quantification method. Meanwhile, different factors in line actual operation transformer. also verify effectiveness accuracy method, which provides new judgment idea for grid quantitative assessment.