Thermal Modelling of Power Transformers

  Nileshkumar Patel,  Pankti Shah

Power transformers represent the largest portion of capital investment in transmission and distribution substations. In addition, power transformer outages have a considerable economic impact on the operation of an electrical network. One of the most important parameters governing a transformer’s life expectancy is the hot-spot temperature value. The classical approach has been to consider the hot-spot temperature as the sum of the ambient temperature, the top-oil temperature rise in tank, and the hot-spot-to-top-oil (in tank) temperature gradient. When fibre optic probes were taken into use, winding hottest spot temperatures higher than those predicted by the loading guides during transient states after the load current increases, before the corresponding steady states have been reached. This paper presents new and more accurate temperature calculation method taking into account for findings hot spot temperature using IEEE standard using computer programming.

Keywords- power transformers, hot-spot temperature, top-oil temperature, bottom-oil temperature, non-linear thermal resistance, oil time constants.

Unique Identification Number - IJEDR1501067
Page Number(s) - 362-367
Pubished in - Volume 3 | Issue 1 | Jan 2015
DOI (Digital Object Identifier) -   
Publisher - IJEDR (ISSN - 2321-9939)

  Nileshkumar Patel,  Pankti Shah,   "Thermal Modelling of Power Transformers", International Journal of Engineering Development and Research (IJEDR), ISSN:2321-9939, Volume.3, Issue 1, pp.362-367, Jan 2015, Available at :http://www.ijedr.org/papers/IJEDR1501067.pdf