Temperature Effect on Dielectric and AC Breakdown Properties of the Cellulose Insulation Paper Immersed in Mineral-Palm Oil Mixture

Abstract

Mixed oil is considered as an ideal insulating fluid for its great physicochemical and insulation properties. A novel mixed oil consisted of 75 vol.% mineral oil and 25 vol.% palm oil, was developed by our team and its main properties basically come up the standards of IEC 60296:2012. In this study, the dielectric properties of mineral oil-impregnated paper (MIN-IP) and mixed oil-impregnated paper (MIX-IP), were comparative analyzed at 25 °C-65 °C, including relative permittivity and dielectric loss factor. The temperature effect on AC breakdown properties for MIN-IP and MIX-IP were also researched at 25 °C-75 °C. The result shows that MIX-IP have higher relative permittivity and dielectric loss factor than MIN-IP. The difference on dielectric strength between MIN-IP and MIX-IP is more significant at 45 °C to 65 °C.