Ageing and Partial Discharge Patterns in Oil-Impregnated Paper and Pressboard Insulation at High Temperature
The power transformer is the most expensive, indispensable and arguably the most important equipment item in a power system Insulation failure in transformers can cause long term interruption to supply and loss of revenue and the condition assessment of the insulation is thus an important maintenance procedure. Oil-impregnated transformer insulation consists of mainly organic materials including mineral oil and cellulose-base paper and pressboard. The operating life of cellulose-based insulation, as with most organic insulation, depends heavily on its operating temperature rise above ambient. This paper reports results of a laboratory-based experimental investigation of partial discharge (PD) activity at high temperature in oil-impregnated insulation. The experiments reported here are part an on-going programme aimed at investigating the way in which insulation deterioration can be monitored and quantified by use of partial discharge diagnostics. Partial discharge patterns were recorded and analysed during increasing and decreasing phases of the temperature. The effect of ageing of the insulation on the PD patterns in oil and oil-impregnated insulation are also considered.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1055625Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF
 R. H. Khawaja and T. R. Blackburn, "Partial Discharge Patterns in Oil- Impregnated Paper and Pressboard Insulation at High temperature", Proceedings of 2008 Australian Universities Power Engineering Conference (AUPEC 08), Sydney, Australia, 14-17 December 2008.
 R. H. Khawaja, "Monitoring of High Voltage Oil-Impregnated Transformer Insulation", Ph.D. dissertation, University of New South Wales Sydney, Australia, 2006.
 R. E. James, et al, "Effect of Moisture and Temperature on PDs in Oil- Impregnated Insulation", Proceedings of the Australasian Universities Power Engineering Conference (AUPEC), Sydney, Vol. 3, pp. 607-614, 1997.
 T. K. Saha, et al., "Investigating the Effect of Thermal Degradation on the Properties of Power Transformer Insulation", IEEE Transaction on Power Delivery, Vol. 14, No. 4, pp. 1359-1367, October 1999.
 F. H. Kreuger, et al., "Classification of Partial Discharges", IEEE Transaction on Electrical Insulation, Vol. 28, No.6, pp. 917-931, 1993
 B. T. Phung, "Computer-Based Partial Discharge Detection and Characterisation", Ph.D. dissertation, University of New South Wales Sydney, Australia, 1997.
 High Voltage Test Techniques - Partial Discharge Measurements, IEC Standard 60270, 2000.