Thermal Degradation of Cellulose Paper Insulation in Power Transformers

This paper presents on experimental on cellulose paper insulation and mineral insulating oil in power transformers. These materials were aged in specially designed glass cells at 140,150and 160 centigrade for ageing times. These measurements show that the loss of strength results from level varies of carbon monoxide and carbon dioxide. Paper tensile strength when combined and correlated with the amount of carbon monoxide and carbon dioxide gases in oil provides a good assessment of the condition of transformers cellulose insulation. Also it is suggested that the loss of tensile strength would provide an end of life criterion for predicting insulating paper life. Therefore a new paper expected life time model is developed.