Ranking of Priorities for the Management of Distribution Transformers: a Multicriterial Approach

One of the most important equipment of the Bulk Power System (BPS) is the Distribution Transformer (DT), which performs a great effort during critical demand. The operation of the DT is correlated to the lifetime of the insulation, consisting of general guidelines of the paper and oil. The durability of the transformer insulation is related to thermal supportability and the equivalent aging factor. Thus, its lifetime depends on the burdens supported during operation since the temperature of the windings and the insulating oil is proportional to the power loading in the transformers. Usually, Power Utilities (PU) without any previous study wait for problems to happen first, and then make solutions. This paper proposes a study of a multicriteria analysis for decision making in DT management using the Analytic Hierarchy Process (AHP) method. The following decision-making criteria are adopted: a lifetime forecast and equivalent aging factor of the DTs, reliability indicators, the impact of proximity to load centers and the distance from the DTs to the feeder. Based on the AHP, the objective of this paper is to provide a ranking that supports the decision making of the replacement priority or even reallocation of the equipment.