A Simple Model for Calculating Transformer Hot-Spot Temperature
ABSTRACT 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.
- SourceAvailable from: Yuan Gao
Conference Paper: Numerical Analysis of Winding Temperature Field for Dry Type Transformer[Show abstract] [Hide abstract]
ABSTRACT: On the base of analysis winding characteristics for a dry type transformer, the simplified model of winding temperature field is established. Then, the winding temperature field is calculated by using finite volume method (FVM) and its distribution rules are analyzed and obtained. Finally, validation of hot pot temperature is confirmed by comparison of both calculating and testing result.Electromagnetic Field Problems and Applications (ICEF), 2012 Sixth International Conference on; 01/2012
- [Show abstract] [Hide abstract]
ABSTRACT: On the transformer, the effect of thermal stress is aging of the solid insulation. Excessive thermal stress could damage the solid insulation. To avoid this, transformer condition monitoring systems could use thermal models to forecast the operating temperatures during dynamic loading. There are several thermal models of varying complexity, including the thermal models stipulated by the IEC and IEEE standards. In this paper, the thermal model which is referred to by IEC Std. 60076-7 as the differential method, is modified, so it accounts for the oil viscosity dependence on temperature. The model is validated using hot-spot temperature measurements from a 40-MVA transformer, OFAF-cooled, 21/115 kV which is located in the subarctic climate region.Condition Monitoring and Diagnosis (CMD), 2012 International Conference on; 01/2012