Recent advances in the analysis and interpretation of aged insulation from operating power transformers

This paper reports on continuing work undertaken within the authors organization in the analysis and interpretation of aged insulation from operating power transformers. The paper cites the results of a recent survey supporting the need for more research in this field and describes some recent advances in technique for estimating remaining insulation life through assessment of furan content in the oil and degree of polymerisation of the insulating paper. The stability and partition coefficients of the furan compounds have been recently investigated and an inter-laboratory collaborative trial is also reported on