The use of diagnostic testing of insulating oil for fault detection in electrical equipment

The operating health of oil-filled electrical equipment can often be determined by the extent of degradation of the insulating fluid. This paper examines the basis for the analytical techniques that are used to correlate the composition of dissolved gases with operational faults such as partial discharge, pyrolysis and arcing. With suitable modifications, these methods can be applied to transformers, load-tap changers, no-load tap changers and circuit breakers.