Comprehensive Assessment of Transformer Insulation Condition Based on Extension Theory

Abstract

Due to the fuzziness and uncertainty of the transformer’s insulation state by itself, when using the index to evaluate the insulation of oil paper transformers alone, the insulation state of transformers may appear contradictory and incompatible situations. This paper establishes evaluation models of extension theory to comprehensively evaluate the state of the oil-paper insulation transformers. Firstly, it establishes multilevel framework of the transformer and determines the weight coefficient of each index by means of extensive AHP; Then, this paper establishes the classical domain and joint domain of transformer’s four kinds of matter-element models using large amounts of the measured data;Finally, using correlation function to determine the insulation state of transformers to be evaluated, this paper realizes the synthetic evaluation with the qualitative and quantitative combination for the transformer. The validity and feasibility of the method are proved by the example in this paper.