Hundred years of experience in the dynamic thermal modelling of power transformers

Loading capability of transformers depends strongly on their thermal conditions which can be investigated by means of a dynamic thermal model. It is typically a set of simple differential equations representing very complex physical phenomena; however, there are several factors affecting the accuracies of the models which should be kept in mind while using these models. This study provides a review on the dynamic thermal models of power transformers from very simple to rather complex thermal models proposed in the last hundred years, the affecting factors on their accuracies, and their fields of applications. It is worthwhile to note that this study focuses on the thermal models which are simple and accurate and able to be integrated into monitoring systems.