Review of time-domain polarization measurements for assessing insulation condition in aged transformers

This paper presents a review of the time-domain polarization measurement techniques for the condition assessment of aged transformer insulation. The polarization process is first described with appropriate dielectric response theories and then commonly used polarization methods are described with special emphasis on the most widely used "return voltage" (RV) measurement. Most recent emphasis has been directed to techniques of determining moisture content of insulation indirectly by measuring RV parameters. The major difficulty still lies with the accurate interpretation of return voltage results. This paper investigates different thoughts regarding the interpretation of RV results for different moisture and ageing conditions. Other time domain polarization measurement techniques and their results are also presented in this paper.

[1]  E. Ildstad,et al.  Modelling return voltage measurements of multi-layer insulation systems , 1994, Proceedings of 1994 4th International Conference on Properties and Applications of Dielectric Materials (ICPADM).

[2]  Tapan Kumar Saha,et al.  Investigation of interfacial polarization spectra parameters for accelerated aged oil-paper invsulation and its correlation with molecular weights and Furan compounds , 2000 .

[3]  U. Gafvert,et al.  Measurement and modeling of dielectric response of composite oil/paper insulation , 1997, Proceedings of 5th International Conference on Properties and Applications of Dielectric Materials.

[4]  W. S. Zaengl,et al.  Time domain measurements of dielectric response in oil-paper insulation systems , 1996, Conference Record of the 1996 IEEE International Symposium on Electrical Insulation.

[5]  W. Zaengl,et al.  A novel, compact instrument for the measurement and evaluation of relaxation currents conceived for on-site diagnosis of electric power apparatus , 2000, Conference Record of the 2000 IEEE International Symposium on Electrical Insulation (Cat. No.00CH37075).

[6]  T. K. Saha,et al.  Experience with Return Voltage Measurements for Assessing Insulation Conditions in Service Aged Transformers , 2002, IEEE Power Engineering Review.

[7]  Tapan Kumar Saha,et al.  Electrical and chemical diagnostics of transformers insulation. A. Aged transformer samples , 1997 .

[8]  I. Kispal,et al.  Spectrum of polarization phenomena of long time-constant as a diagnostic method of oil-paper insulating systems , 1991, [1991] Proceedings of the 3rd International Conference on Properties and Applications of Dielectric Materials.

[9]  Erling Ildstad,et al.  Relation between return voltage and other methods for measurements of dielectric response , 1994, Proceedings of 1994 IEEE International Symposium on Electrical Insulation.

[10]  A. Krivda,et al.  Assessment of oil impregnated paper insulated transformers using recovery voltage measurements , 1998, ICSD'98. Proceedings of the 1998 IEEE 6th International Conference on Conduction and Breakdown in Solid Dielectrics (Cat. No.98CH36132).

[11]  Yu Xingzhou,et al.  Study of recovery voltage mechanism [transformer insulation diagnosis] , 2000, Proceedings of the 6th International Conference on Properties and Applications of Dielectric Materials (Cat. No.00CH36347).

[12]  M. Webb,et al.  Polarisation spectrum analysis for diagnosis of insulation systems , 1992 .

[13]  Tapan Kumar Saha,et al.  Electrical and chemical diagnostics of transformers insulation. B. Accelerated aged insulation samples , 1997 .

[14]  G. Csepes,et al.  Practical foundations of the RVM (recovery voltage method for oil/paper insulation diagnosis) , 1998, 1998 Annual Report Conference on Electrical Insulation and Dielectric Phenomena (Cat. No.98CH36257).

[15]  A. Krivda,et al.  Assessment of insulation condition of 130 kV oil-paper current transformers using return voltage measurements and an expert system , 1997, IEEE 1997 Annual Report Conference on Electrical Insulation and Dielectric Phenomena.

[16]  E. Nemeth,et al.  Measuring voltage response: a non-destructive diagnostic test method of HV insulation , 1999 .

[17]  L. Adeen,et al.  Dielectric spectroscopy in time and frequency domain applied to diagnostics of power transformers , 2000, Proceedings of the 6th International Conference on Properties and Applications of Dielectric Materials (Cat. No.00CH36347).

[18]  Tapan Kumar Saha,et al.  Investigating the effects of oxidation and thermal degradation on electrical and chemical properties of power transformers insulation , 1999 .

[19]  Syed Islam,et al.  Modeling the polarization spectrum in composite oil/paper insulation systems , 1999 .

[20]  Tapan Kumar Saha,et al.  Investigations into effective methods for assessing the condition of insulation in aged power transformers , 1998 .

[21]  G. M. Urbani,et al.  Using the recovery voltage method to evaluate aging in oil-paper insulation , 1998, ICSD'98. Proceedings of the 1998 IEEE 6th International Conference on Conduction and Breakdown in Solid Dielectrics (Cat. No.98CH36132).