Application of interactive multiple models in thermal modeling of power transformers

Abstract

Power transformers are one of the most expensive equipments in power systems. The efficiency and optimal utilization of these equipments are very important issues. Some factors, like temperature, moisture and oxidation can affect the solid and liquid insulations and reduce the useful life of power transformer. Temperature of a power transformer depends on the ambient temperature, present and past loading and cooling classes. Proper thermal model is essential to predict temperature in different conditions of cooling system. Such model leads to analyze useful life and improve loading and utilization of a power transformer. In this contribution a thermal model for power transformers based on the new technique of Interactive Multiple Modeling (IMM) is suggested to predict the top-oil temperature. Practical validation is carried out with measured load and temperature data of a power transformer. Consequently the prediction error for the conventional thermal model and the new suggested model based on IMM technique are compared. Copyright © 2011 John Wiley & Sons, Ltd.