Multi‐criteria decision‐making methods for grading high‐performance transformer oil with antioxidants under accelerated ageing conditions.

In this study, different types of antioxidants (AO) such as natural and synthetic AOs are mixed with mineral oil (MO) at various individual and grouping concentrations to enhance the life of transformers. Water content in oil, water content in paper, breakdown voltage, acidity, 2‐furaldehyde concentration, degree of polymerisation and tensile strength are the laboratory‐based ageing‐related performance characteristics considered in the proposed work to evaluate the degradation rate of MO samples. Multi‐criteria decision‐making methods such as analytic hierarchy process (AHP) and technique for order preference by similarity to ideal solution (TOPSIS) are used to identify the sample concentration which gives maximum performance while considering all the characteristic performance of the MO samples precisely. Two different methods are employed to assess the performance characteristics of the MO samples. In first method, AHP is employed for both priority weight calculation and ranking of MO samples. In second method, AHP is used for weight calculation and TOPSIS is used for ranking. From the experimental results, it is found that, the MO sample S5 yields better performance when compared with other samples. Hence, it is suggested that MO sample S5 can be the best alternative for transformer oil. [ABSTRACT FROM AUTHOR]