Dielectric characterization of power transformer oils as a diagnostic life prediction method

The monitoring of the complex permittivity of transformer oils as a function of frequency and temperature provides information concerning the state of the insulation. In this work, it has been investigated as a quality control method, providing service life estimations of power transformations. The formation of databases recording polarization effects in a wide frequency and temperature range may be used effectively as a working tool for service engineers. Reliable insulation monitoring reduces accidents in aged HV transformers, some of which have been in operation since the 1960s. These transformers always impose an environmental threat because of possible accidental leaks or fires, especially when containing traces of PCBs.

[1]  W. S. Zaengl,et al.  Dielectric Response Methods for Diagnostics of Power Transformers , 2003 .

[2]  C. Holdren,et al.  Toxics A to Z: A Guide to Everyday Pollution Hazards , 1991 .

[3]  Michel Duval,et al.  A review of faults detectable by gas-in-oil analysis in transformers , 2002 .

[4]  T. V. Oommen,et al.  New insulating fluids for transformers based on biodegradable high oleic vegetable oil and ester fluid , 1999 .

[5]  M. Ali,et al.  The transport of copper through oil-impregnated paper insulation in electrical current transformers and bushings , 2003 .

[6]  H. Borsi,et al.  Dielectric behavior of silicone and ester fluids for use in distribution transformers , 1991 .

[7]  V. T. Morgan,et al.  Effects of frequency, temperature, compression, and air pressure on the dielectric properties of a multilayer stack of dry kraft paper , 1998 .

[8]  B. H. Ward,et al.  A survey of new techniques in insulation monitoring of power transformers , 2001 .

[9]  Hossein Borsi,et al.  Fundamental investigations on some transformer liquids under various outdoor conditions , 2001 .

[10]  T. Oommen.  Vegetable oils for liquid-filled transformers , 2002 .

[11]  E. Gockenbach,et al.  Retrofilling conditions of high voltage transformers , 2001 .

[12]  R. Ferguson,et al.  Suspended particles in the liquid insulation of aging power transformers , 2002 .

[13]  M. Shibuya,et al.  Solvent cleaning of pole transformers containing PCB contaminated insulating oil. , 2001, Waste management.

[14]  W. S. Zaengl,et al.  Dielectric spectroscopy in time and frequency domain for HV power equipment. I. Theoretical considerations , 2003 .

[15]  Michel Duval,et al.  Interpretation of gas-in-oil analysis using new IEC publication 60599 and IEC TC 10 databases , 2001 .

[16]  T. Ishii,et al.  Changes in ECT and dielectric dissipation factor of insulating oils due to aging in oxygen , 2001 .

[17]  Mohamed A. A. Wahab,et al.  Novel modeling for the prediction of aged transformer oil characteristics , 1999 .

[18]  V. G. Arakelian,et al.  Effective diagnostics for oil-filled equipment , 2002 .