Comprehensive Analysis of the Condition of Power Transformers in the DACH Region: A Focus on Typical Gas Levels for TSOs and DSOs

Inhalt:
The studies carried out in IEC 60599 and IEEE C57.104 determine the typical gas levels of power transformers world-wide. A major advantage of this considerable amount of data is its high statistical significance. As in both studies, network operators are recommended to determine their own typical gas levels in order to confirm that the selected standards (IEC, IEEE) are appropriate for their transformer fleet. If it is not possible to determine their own gas levels, either because the history of oil reports is too short or the collective is too small, operators can take the values from the studies as a first step. An understandable disadvantage here is the lack of transparency, transferability and comparability for individual network operators, as the studies compare power transformers from all over the world. Local guidelines, loads, grid struc-tures and environmental influences can differ greatly here. For network operators from the DACH region (D: Germany, A: Austria, CH: Switzerland) or comparable regions, this paper offers valuable information on typical gas levels. In ad-dition, a distinction is made between transmission system operators (TSOs) and distribution system operators (DSOs) to reflect different construction methods, maintenance strategies and electrical, mechanical and thermal loads. The typical gas levels from the studies are compared with an extensive database of transformers from the DACH region.