[224] Integrating data from transformer condition monitoring to support asset management decisions

M Rowbottom1, Jamie Beardsall1, R Heywood2, P Boreham2 and T McGrail3

1Drax Power, UK
2Doble PowerTest, UK
3Doble Engineering, USA 

This paper describes experience with condition monitoring of large generator step-up transformers and associated unit transformers. Diagnostics include the use of bushing power factor/capacitance together with several partial discharge methods for both bushing and main tank sources and online dissolved gas analysers for the insulating oil. A number of cases have been recorded in which condition monitoring data seems to indicate a problem with a bushing or with a transformer, but inclusion of contextual data has permitted a more thorough analysis and evaluation, supporting appropriate asset decisions. The link between technical data and asset management decisions will be discussed.