Quality assessment operating oil power transformers 35−110 kV

Analyzed is the existing approach to evaluation of technical conditions of 35−110 kV power transformers relying on the results of physicochemical analysis of insulating oils, the drawbacks of such approach pointed out.

Proposed is a system for more adequate evaluation of operational transformer oil parameters and measures for its serviceability recovery and prolongation.

One has demonstrated the necessity: to introduce a new indicator of operational transformer oils quality — «oxidation stability»; revise the threshold values of the acidity index, of content of water-soluble acids and alkali, oil dielectric loss angle tangent, content of agidol-1 (ionol) antioxidant additive in oils filled into 35 — 110 kV power transformers without dedicated oil protections; revise the scope of indicators to be measured for scheduled physicochemical analysis of oil samples established for 35−110 kV power transformers without dedicated oil protections.