The Ageing Performance of Novel GtL-Oil in Comparison to Conventional High Grade Insulation Oils

This article describes a comparative ageing test between a novel insulation oil based on gas-to-liquid oils (Shell Diala S4 ZX-I) and crude-oil based high-performance oils (Shell Diala D, Shell Diala S3 ZX-I und Nynas Nytro 4000X). Ageing was carried out at 120°C temperature, under the presence of typical transformer materials (cellulose-based and copper) and under the presence and the absence of oxygen from the atmosphere. The accelerated ageing test shows a very good ageing stability of the new GtL-oil and superior performance in comparison to the other oils in this test. The new GtL-oil can be identified in its IR spectrum. Though all chemical parameters showed heavy ageing, the breakdown voltage remained constant for all oils. The capability to dissolve moisture doubled for all oils.…