Power Transformers Loss Of Life Evaluation Using Winding Insulation Resistance Calculation Model

The conventional calculation of the loss of life of power transformers is based on IEC and IEEE thermal models that are used already for a long time in the energy sector to evaluate the ageing of transformers and they are integrated in most of the condition monitoring systems. Due to some recent research studies, there was determined a new method to calculate the lost and remaining lifetime of power transformers, based on a new model that is using the values of winding insulation resistance. In this paper, will be presented a study were this new ageing evaluation model will be used to calculate the loss of life of several power transformers installed in the Romanian transmission power grid. The results of this case study will be statistically compared with the results of the conventional thermal model, using data from the condition monitoring systems installed on the power transformer.