Analysis on the solute generating from PPS in transformer oil after electro-thermal aging

Abstract

The poor thermo stability and electrical properties of insulation paper used in an oil-immersed transformer would limit the performance and size of the transformer. In order to substitute insulation paper, we chose polyphenylene sulfide (PPS) as the object of study to make research on its electro-thermal aging characteristics. We tested PPS's dielectrical, physical, chemical and mechanical properties before and after aging, and researched on its resultant solute in oil after aging. It can be concluded from infrared spectral analysis of PPS that a kind of small-molecule compound that contains C=O carbonyl generates from PPS after electro-thermal aging, and the resultant can be dissolved in petroleum ether. Combining with the mass spectrum analysis of transformer oil, we preliminarily confirm the molecular structural formula of the resultant, which is aldehyde with molecular weight of 242. Further research needs to make on the content of the solute in oil at different aging stages, with the expectation of aging diagnosis on PPS-oil insulation.