DEGRADATION OF ELECTRICAL INSULATING PAPER MONITORED WITH HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

Furans are amongst the decomposition products which are generated by the degradation of cellulose in paper. Paper insulation is used in capacitors, cables and transformers. These furans dissolve in the impregnating mineral oil, and a method, involving the use of high performance liquid chromatography, has been developed to determine their concentration in the oil. The degradation of electrical Kraft paper under carefully controlled laboratory experiments is being examined in order to find correlations between the change in dielectric and mechanical properties and the increase in concentration of furan compounds in the oil. These correlations could be valuable for assessing the extent of degradation of paper insulation in operating HV equipment. We have found that only three of the furan compounds are sufficiently stable for this purpose. © 1990 IEEE