Ageing Behaviour of High-Voltage Transformers in the DACH Region

The average age of power transformers worldwide is around 40 years. Due to the advancing age of the transformer population, knowledge about their ageing behaviour is becoming increasingly important. Within the framework of the research project “AHtra” (Ger.: “Alterungsverhalten von Hochspannungstransformatoren”; Eng.: “Ageing behaviour of high-voltage transformers”), over 3,500 transformers from 36 network operators from the DACH region (Germany, Austria, Switzerland) are being uniformly assessed for the first time. Based on the condition-dependent evaluations of the transformers, the actual ageing behaviour can be derived. Oil reports (chemical-physical analyses, dissolved gas analyses and furan analyses), electrical measurements and visual inspections serve as a basis. In addition, general information like voltage level and type of oil will be considered. The total number of analyses that can be drawn from the multitude of transformers amounts to over 36,000 and thus forms a valid database for the prediction of ageing behaviour.