Title :
Dynamic thermal modelling of power transformers
Author :
Susa, Dejan ; Lehtonen, Matti ; Nordman, Hasse
Author_Institution :
Power Syst. Lab., Helsinki Univ. of Technol., Espoo, Finland
Abstract :
The aim of this paper is to introduce hot-spot and top-oil temperature thermal models for more accurate temperature calculations during transient states based on data received in a normal heat run test (i.e., the top oil in the tank of the transformer and the average winding-to-average oil gradient). Oil viscosity changes and loss variation with temperature are taken into account. The new thermal models will be validated using experimental (fiber-optic test) results obtained at varying load current on a 250-MVA-ONAF-cooled unit, a 400-MVA-ONAF-cooled unit and a 605-MVA-OFAF-cooled unit. The results are also compared with the IEEE-Loading guide (1995) Annex G method.
Keywords :
power transformers; temperature; transformer oil; viscosity; 250 MVA; 400 MVA; 605 MVA; Annex G method; IEEE loading guide; dynamic thermal modelling; fiber optic test; hot spot temperature; oil viscosity; power transformer; top-oil temperature thermal model; varying load current; Capacitance; Cooling; Oil insulation; Petroleum; Power transformer insulation; Power transformers; Temperature; Testing; Thermal resistance; Viscosity; Hot-spot temperature; power transformer; top-oil temperature;
Journal_Title :
Power Delivery, IEEE Transactions on
DOI :
10.1109/TPWRD.2004.835255
