Insulation cellulose paper is a basic measure for a power transformer’s remaining useful life, and its advantageous low cost, electrical, and mechanical properties have made it an extensive insulation system when impregnated in a dielectric liquid. Cellulose paper deteriorates as a result of ageing due to some chemical reactions like pyrolysis (heat), hydrolysis (moisture), and oxidation (oxygen) that affects its degree of polymerization. The condition analysis of cellulose paper has been a major concern since the collection of paper samples from an operational power transformer is almost impossible. However, some chemicals generated during cellulose paper deterioration, which were dissolved in dielectric liquid, have been used alternatively for this purpose as they show a direct correlation with the paper’s degree of polymerization. Furthermore, online and non-destructive measurement of the degree of polymerization by optical sensors has been proposed recently but is yet to be available in the market and is yet generally acceptable. In mitigating the magnitude of paper deterioration, some ageing assessments have been proposed. Furthermore, researchers have successfully enhanced the insulating performance of oil-impregnated insulation paper by the addition of various types of nanoparticles. This study reviews the ageing assessment of oil-paper composite insulation and the effect of nanoparticles on tensile strength and electrical properties of oil-impregnated paper insulation. It includes not only significant tutorial elements but also some analyses, which open the door for further research on the topic.
Vegetable oil has shown a promising behaviour in replacing mineral insulating oil for transformer insulation due to the environmental unfriendliness of mineral oil. However, attention was placed mostly on the edible oil which may eventually lead to food competition. In this work ester from Thevetia Peruviana oil, non-edible vegetable oil was considered as alternative oil for transformer insulation. The functional groups and the ngerprints of the synthesized methyl ester from the Yellow oleander oil were con rmed using Fourier Transform Infrared (FTIR) Spectrometry and the fatty acid composition was determined with Gas chromatography mass spectrometry (GC/MS). The viscosity of the methyl ester and mineral oil were obtained to be 4.8 mPas and 9.8 mPas at 30°C. The pour point of methyl ester was obtained to be 1.4°C which could be enhanced by a pour point depressant when considering it for use in a low temperate region. The adequacy of this synthesized oil as an insulating oil was further explored by measuring the dielectric properties. The result revealed that methyl ester has a higher dielectric constant relative to mineral oil and a dielectric loss of 0.0045 at 30°C. The dielectric strength of the oil was analysed using two-parameter Weibull plots. The characteristic breakdown strength of mineral oil and yellow oleander methyl ester was obtained to be 21.9 kV and 23.3 kV respectively. The result obtained from this work is an indication that methyl ester from the non-edible vegetable oil is a promising alternative insulating oil for oil-lled transformer insulation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.