Temperature prediction on power transformers and the guide on load dispatch

Transformer winding temperature is a function of the load current and ambient temperature. As the maximum winding temperature at steady state operation is limited by IEEE/IEC standards, the higher the ambient temperature, the lower the permitted current. When the high temperature warning forecast from government climatological stations is available, the maximal load can be pre-calculated and, if necessary, the extra load can be pre-shifted to other transformers. This can help the dispatchers of power grid to prearrange the load in the power network from the 3-day to 7-day weather forecast of the climatological stations. This paper used the Finite Element approach to calculate the electrical-thermal-fluid dynamic phenomena in the power transformer. The results gave the relationship between winding temperature, load current, and the ambient temperature. A four dimension interpolation method is employed to give a good prediction of the power station temperature from the data of the climatological stations around. The four dimensions used include the longitude, the latitude, the altitude, and the time of the power stations and the climatological stations, respectively. The final results are discussed and possible applications are presented.