Determining Insulation Condition of 110kV Instrument Transformers Using Gas Chromatography

The paper dwells on determining insulation condition of high voltage instrument transformers and contains both theoretical contributions and measurements (performed on electrical equipment in 110/20kV substations in Sibiu county, Romania) regarding, namely, the partial discharge phenomena, highlighted using gas chromatography. Measurements have shown the negative effects of these internal possible mechanisms, such as arcing, corona discharges, spark discharges (local penetrations of insulation, possessing a high density of ionization or appearance of low energy arcing, sometimes described – not as an absolute rule – as partial discharge), on the solid insulation of high voltage instrument transformers. These conditions occurring singly or as several simultaneous events can result in decomposition of the insulating materials and the formation of various combustible and noncombustible gases. The technique used by the authors proved itself to be up to date, extremely advantageous, with extraordinary precision, speed and handling flexibility. Very reproductive results recommend the use of gas chromatography.