Constellation, le dépôt institutionnel de l'Université du Québec à Chicoutimi

Résumé

Liquid insulation, a key element in the transmission and distribution of electric power, guarantees safe operation from power transformers, cables, circuit breakers etc. by successfully transferring heat from the equipment as well as acting as the electrical insulating medium. In liquid insulation, mineral oil is widely used as an insulating medium in power industries. In the first part of this research project the impact of the aging of mineral oil on partial discharge is investigated as well as on other chemical and physical properties. For different accelerated aging times, different experiment are set up so that the aforementioned impact is measured along with several other parameters. Investigations are also performed on new oil to provide baseline comparison. The aim of this part of the research is to find relationships between partial discharge inception voltage (PDIV) and the other parameters of oil to do a suitable interpretation between them during aging time. Recently, interest has been growing in enhancing the insulating properties of mineral oil by adding nanoparticles. The literature survey revealed the promising impact of TiC>2 nanoparticles. In the second part of this project, the dielectric performance of mineral oil was therefore investigated by adding different concentrations of TiO2 nanoparticles (from 0.003 g/ml to 0.01 g/ml) using ultrasonic methods. All the investigation tests were performed at different temperatures ranging from -47 to 47°C to correspond with environmental temperature changes in Canada. The results were compared in terms of breakdown and dielectric properties, such as permittivity and resistivity.