The Economic Life Assessment of Transformer Based on Random Fuzzy Theory

Abstract

According to the Life Cycle Cost theory, the paper sets up the Life Cycle Cost model of the transformer that covers initial investment cost, operation cost, failure cost and retirement cost, and puts forward a new concept of economic life, determining the economic life of transformer through comparing the annual net profit of the old transformer with the largest annual net profit of the new transformer. As the transformer serves for a long time and the running environment is complicated, parameters, which are required for in evaluation, are both random and fuzzy. Then, introduce random and fuzzy theory that can handle the uncertainties at the same time to assess the economic life of the transformer. This model not only can get the expectancy of economic life of the transformer, but also can get the economic life interval under different confidence level and the economic life interval whose chance measure is the biggest under the same economic life span. Finally, take the assessed transformer as a example to verify the rationality and validity of the model.