Determination of steady-state temperature rises of power transformers

The methods of determining steady-state temperature rises specified in present standards for power transformers do not ensure reliable and accurate determination of steady-state temperature rises. Therefore, improvements of temperature rise test procedures and of methods of determining steady-state temperature rises are proposed. The application of these improvements provides a more accurate determination of the steady-state temperature rises of power transformers in conjunction with savings of energy and time. The methods described can be applied to all temperature rise tests, provided that the relevant part of the temperature rise curves can be approximated by a simple exponential function.