Electricity Today T&D Magazine

Dissolved gas analysis (DGA) in transformers is a very successful periodic screening method to identify transformers that may be having problems. It is a symptom-based assessment of health, rather than a condition-based assessment. That is because the gases themselves do not cause failure, but are just by-products of deteriorating insulation caused by abnormalities such as
hot spots or electrical discharges. The abnormalities are what might fail the transformer. If the transformer loses fault gases, the...