Total views : 212

Insulation Assessment of Oil Impregnated Paper Condenser Bushings using Dielectric Frequency Response Technique


  • Department of Electrical Engineering, Bharati Vidyapeeth Deemed University, College of Engineering, Pune – 411043, Maharashtra, India
  • Department of Electrical Engineering, Army Institute of Technology, Pune – 411015, Maharashtra, India


Objectives: Investigation of insulation to judge the health of the condenser bushing with different techniques has been the area of interest for the researchers in recent past. Power transformers and their bushings are manufactured with oil impregnated paper insulation but their insulation integrity is comprised due to absorbed, residual or liberated moisture/ water which leads to further deterioration and catastrophic failure. Methods: Conventional measurement technique taken at rated power frequency only gives relative indication of specific dielectric properties and health of the condenser bushings. This article introduces a new approach for insulation assessment of the condenser bushings where OIP insulation as a key component has been investigated in a wide frequency response spectrum and to confirm the validity of this approach, measurements were taken on several condenser bushings of same type and age. Findings: The advance technique is a nondestructive method which evaluates the water concentration of the test object. The resulting curve is highly determined by the behavior of solid insulation and it is also sensitive to oil conductivity and insulation geometry of the bushing. Furthermore, the interpretation scheme related to dielectric response is explained. Applications: The signatures achieved helps in reliable data analysis and can be used in qualitative comparisons of bushings which compliments the available quality assurance techniques in the factory. This approach can also be used for frequent monitoring and effective moisture management at site.


Condenser Bushing, Dielectric Spectroscopy, Insulation Assessment, Oil and Paper Insulation

Full Text:

 |  (PDF views: 135)


  • Sagar B, Parashuram K. New Approach to Assess the Insulation Condition of Condenser Bushings. Proceedings of International Conference on Recent Trends in Engineering and Technology (ASCTET), India, 2016 Oct.
  • Guan Z, Jian W, Shuang Y, Ming D. Investigation on dielectric response characteristics of thermally aged insulating pressboard in vacuum and oil-impregnated ambient. IEEE Transactions on Dielectrics and Electrical Insulation, 2010.
  • Betie A, Meghnefi F, Fofana I, Yeo Z. Neural network approach to separate aging and moisture from the dielectric response of oil impregnated paper insulation, IEEE Transactions on Dielectrics and Electrical Insulation, 2015.
  • Maik K, Michael K, Markus P. Advanced Insulation Diagnostic by Dielectric Spectroscopy. Omicron Publication, 2011 Dec.
  • Mark G. Substation Equipment (Bushings). Tennessee Valley Authority. 2010;5: 7–9.
  • Lars J, Rutger J. High-voltage bushings-100 years of technical advancement. ABB Review. 2009 Mar; 3:66–70.
  • Maik K, Micheal K, Kraetge A. A Comparative Test and Consequent Improvements on Dielectric Response Methods. Proceedings of the 15th International Symposium on High Voltage Engineering. 2007 April.
  • Gobi S, Aizam T. TNB Experiences Using Dielectric Response Technique to Assess High Voltage Insulation of high voltage current transformer. International Journal of Energy Engineering. 2013 April;3(2):1–12.
  • Kenneth C. Dispersion and Absorption in dielectrics.Department of Physiology, Melaka Technical University: Malaysia. 2013 June.
  • Tapan S. Review of Time Domain Polarization Measurement for Assessing Insulation Condition in Aged Transformer.IEEE Transaction on Power Delivery. 2003;4(18):1297–1.
  • Walter Z. Dielectric spectroscopy in time and frequency domain for HV power equipment. 12th International Symposium on High Voltage Engineering, India. 2001.
  • Duplessis E, Jill C. Advanced transformer diagnostics.POWERGRID International, 2010 Dec.
  • Daisy S, Sundara R. Study of Frequency Domain Spectroscopy on model transformer windings at elevated temperatures. Proceedings of 11th International Conference on the Properties and Applications of Dielectric Materials (ICPADM), 2015.
  • Michael J. Information within the dielectric response of power transformers for wide frequency ranges. IEEE International Symposium on Electrical Insulation, 2010 June.
  • Agilent. Basics of Measuring Dielectric Properties of Materials. Application note of Agilent Technologies, 2014 Aug.
  • Walter Z. Application of Dielectric Spectroscopy in Time and Frequency Domain for HV Power Equipment. IEEE Electrical Insulation Magazine. 2003;19(6):54–61.


  • »
  • »

Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 License.