The transformer thermal loss of life: Part 2-Influence of functional and structural parameters' variability, A probabilistic approach

International audienceMain factors constraining transformers' thermal loss of life (LOL) are load and ambient temperature profiles they experience. Provided a suitable transformer thermal model and a LOL one are chosen, it is possible, from a theoretical point of view, to determine its on-line expected LOL, as already presented in the first part of this work. However, due to the random character of constrains, such a purely deterministic approach will lead to reduced reliability results. The physical characteristics of the real profiles that transformers are subjected to (deterministic and random), and the uncertainty associated to transformer's specific parameters used in its thermal model, require a probabilistic approach for the study of expected LOL. This part of the work consists of two studies: the estimation of transformer LOL by considering statistical distributions for the load and ambient temperature profiles and the analysis of model's sensitivity to its structural parameters