Condition monitoring and fault diagnosis of an MR load tap changer using oil analyses data
Abstract
Considering the objectives of "condition based preventative maintenance strategy", condition monitoring of an MR M-type load tap changer (LTC) was assessed applying several oil analyses. The analyses consisted of dissolved gas analysis (DGA), breakdown voltage measurement as well as analyses of dissolved metals and suspended particles in oil, were followed by interpretation of the derived data for condition monitoring and fault diagnosis of the pilot LTC.
Finally, the pilot LTC was overhauled after the last oil sampling and the observations from eye inspection were compared to the extracted results from oil analyses data interpretation.
References
ASTM Standard D1816. 2012. Standard test method for dielectric breakdown voltage of insulating oils of petroleum origin using VDE electrodes. Vol. 10.03.
ASTM Standard D 3612-02. 2009. Standard Test Method for Analysis of Gases Dissolved in Electrical Insulating Oil by Gas Chromatography. Vol. 10.03.
ASTM Standard D 3613-98. 1998. Standard Practices for Sampling Electrical Insulating Liquids. Vol. 10.03.
ASTM Standard D 6786-02. 2002. Test Method for Particle Count in Mineral Insulating Oil Using Automatic Optical Particle Counters. Vol. 10.03.
ASTM Standard D 7151-05. 2005. Electrical Insulating Liquids and Gases; Electrical Protective Equipment, Standard Test Method for Determination of Elements Insulating Oils by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). Vol. 10.03.
Cox. R.: The benefits of on-line DGA tap changer monitoring. www.weidmann-diagnostics.com
Duval, M. 2006. Dissolved gas analysis and the Duval triangle. The Fifth AVO New Zealand International Technical Conference. Methven, New Zealand.
Duval, M. 2008A. Calculation of DGA Limit Values and Sampling Intervals in Transformers in Service. IEEE Electr. Insul. M. 24, 5: 7-13.
Duval, M. 2008B. The Duval Triangle for Load Tap Changers, Non-Mineral Oils and Low Temperature Faults in Transformers. IEEE Electr. Insul. M. 24, 6: 22-29.
EPRI Report #1001946. 2001. Development of Load Tap Changer Monitoring Technique: Mechanism of Coking.
EPRI report #1006654. 2001. Transformer Load Tap Changer Management, Diagnostics, Contact Coking, and On-line Oil Filtration.
EPRI report #1012350. 2006. New Equipment and Performance Design Review – LTC Management Course Materials.
Erbrink, J., Gulski, E., Smit, J., Leich, R. 2009. Experimental model for diagnosing on-load tap changer contact aging with dynamic resistance measurements. The 20th International Conference on Electricity Distribution. Prague, Czech Republic.
Handley, B., Redfern, M., White, S. 2001. On load tap-changer conditioned based maintenance. IEE Proceedings Generation, Transmission and Distribution.
IEEE Standard C57.139. 2010. IEEE Guide for Dissolved Gas Analysis in Transformer Load Tap Changers.
Levand, L., Griffin, P. 2004. Condition Assessment of Oil Circuit Breakers and Load Tap-Changers by the Use of Laboratory Testing and Diagnostics, NETA World. 1-4.
Levand, L. 2007. Metals Analysis in Transformers, Load Tap-Changers and Oil Circuit Breakers, NETA World. 1-4.
Lyonnet, P. 1991. Maintenance planning- methods and mathematics, Chapman and Hall, New Delhi, India.
Mackenzie, E.A., Crossey, J., De Pablo, A., Ferguson, W. 2010. On-line Monitoring and Diagnostics for Power Transformers, Application to On-load Tap-changers. IEEE International Symposium on Electrical Insulation. San Diego, California, USA.
Muhamad, N.A., Phung, B.T, Blackburn, T.R., Lai, K.X. 2007. Comparative Study and Analysis of DGA Methods for Transformer Mineral Oil. IEEE Lausanne Power tech. Lausanne, Switzerland.
Redfern, M.A., Handley, W.R.C. 2001. Duty based maintenance for on-load transformer tap changers. IEEE Power Engineering Society Summer Meeting. Vancouver, BC, Canada.
Schellhase, H.U., Wilye, I., Lau, M., Ward, B. 1999. Load tap-changer diagnostics: a critical review of the past ten years. EPRI.
Schellhase, H., Pollock, R.G., Rao, A.S., Korolenko, E.C., Ward, B. 2002. Load Tap Changers: Investigations of Contacts, Contact Wear and Contact Coking. The Forty-Eighth IEEE Holm Conference on Electrical contacts. Orlando, USA.
Youngblood, R., Baker, C., Jakob, F., Perjanik, N. Application of Dissolved Gas Analysis to Load Tap Changers. www.weidmannacti.com