How to deal with gassing transformers

Power transformers are generally reliable constituents of a transmission or distribution network. However, the cost of a transformer failure can be very high, not just the price of a new transformer but also the costs incurred by a forced outage and loss of security to the system. It is certainly, therefore, in the asset owner’s interest to take an informed interest in their condition. Condition assessment and monitoring techniques have received a technological boost in the last few years but at the heart of it is a technique dating back several decades. Dissolved gas analysis (DGA) is still the best technique for detecting abnormalities in transformers. The sampling of oil and subsequent analysis for dissolved gases is well defined in IEC60567 (1). The interpretation of the results is less straightforward; there are recognised standards (2,3) and other publications (4,5). Whilst they

Keywords:

Transformers , Dissolved gas analysis. Furfural analysis , radio frequency interference , condition monitoring