A Simple Model for Calculating Transformer Hot-Spot Temperature

Energy Res. Dept., SINTEF, Trondheim
IEEE Transactions on Power Delivery (Impact Factor: 1.73). 08/2009; 24(3):1257 - 1265. DOI: 10.1109/TPWRD.2009.2022670
Source: IEEE Xplore


A simple model for calculating the hot-spot temperature is introduced. The model is based on the hot-spot to ambient gradient. The model considers the changes of the oil viscosity and winding losses with temperature. The results are compared with temperatures calculated by IEEE Annex G method and measured results at varying load for the following transformer units: 250-MVA ONAF, 400-MVA ONAF, and 605-MVA OFAF.

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    • "IEEE guide [9], [18] and IEC 60354 loading guide for oil-immersed power transformers [16]. In [5], [13], and [17], Swift et al. proposed a basic approach of modelling based on heat transfer theory. The existing models are studied below. "
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