Prediction of hottest spot temperature (HST) in power and station transformers

The degradation of electrical insulation in transformers is more often due to thermal stress. In this paper, the authors attempted to work out a method of assessing the magnitude of temperature and the hottest region in the body of a large transformer with a reasonable degree of accuracy. A theoretical model has been developed based on the boundary value problem of heat conduction in transformer winding using finite integral transform techniques. The model requires, in addition to electrical parameters of the transformer, information on the actual design data. The authors believe that this model predicts HST with precision and also indicates a possibility of online data acquisition.