ITEE Innovation Expo 2008 : Project Details

DGA and its usefulness for transformer condition assessment

In modern times it has become an expectation for power utilities to provide continuous uninterrupted power supply to all consumers, both residential and industrial. To that end the pressure placed on power utilities and hence their assets to meet not only a continuous supply but also allow for various fluctuations in demand, is immense. It is because of this increasing strain that is often placed on electrical equipment in power networks, that there is great value for diagnostic tools that not only detect faults but also predict with great accuracy a potential failure. The purpose of this thesis is to investigate the ongoing effectiveness of Dissolved Gas Analysis (DGA). Dissolved gas analysis is a diagnostic tool widely used by power utilities around the world to perform condition assessments on various assets. By studying the dissolved gasses in the insulating mineral oil one can detect abnormal behaviour taking place inside an asset, prior to failure, preventing potential network outages and interruptions. With new techniques being developed for condition assessments of electrical equipment, a method for prioritising equipment in service with respect to the seriousness of a suspected fault could prove extremely useful to a power utility. Using the interpretation techniques in IEC 60599, results have illustrated various fault types in the sample data set provided by a local power utility with DGA data on existing power and instrument transformers currently in service. These results allow for a customizable priority list to be created based on which faults are determined to require more urgent attention than others.