Investigation of Oil and Winding Temperature Models of Power Transformers

Abstract

The quality of electrical power and serves continuity of electricity is a significant research area for consumer satisfaction and for the reliability of electric system. The prolonged outages of the electricity grid may cause increased power demand during distribution system restoration because of thermostatically control loads. This situation may lead to overloading of the power transformers. Minimization of overload problems and effective restoration of distribution system depend on the determination of power transformer loading limits. Therefore, derivations of dynamic temperature models based on operation conditions and temperature variations should be known for different loadings and time intervals. In this study, top oil and hottest-spot temperatures of power transformers are examined by using IEEE Annex G model and equivalent heat circuit model for different loading conditions, and differences between these models are stated.