Transformer lifecycle: The diagnostic power of oil analysis for power transformers

As blood tests provide information about a person’s state of health, oil analyses provide information about the condition of a transformer. Transformer oil testing has proven to be an excellent tool for early defect identification in preventive maintenance of oil-filled transformers. It has permitted extended service life by giving a measure of both oil and solid insulation condition, and by identifying the presence of incipient thermal and dielectric faults. When performed regularly, oil analysis will help the asset manager run a cost-effective maintenance program for transformers. This column addresses some recent developments in oil analysis, such as sustainable alternatives for mineral oil, an alternative marker for analysis of paper degradation, and online transformer oil monitoring