Condition Assessment Techniques for Insulation Diagnosis of Oil Filled Power Transformers


Dillip Kumar Puhan
Rajat Sharma
K. P. Meena
B. Nageshwar Rao


Power transformers are key components in the substation/switchyard and failure of transformer can have an enormous impact on reliability and availability of power supply and has financial implications. As there is ever increase in demand of power, the reliability of power equipment assumes high importance. Economic factors are the main consideration and in order to minimize capital expenditure on new equipment, it is a common policy among utilities to maximize the use of existing power transformers by operating at their design capability. This can be achieved by periodic diagnostic testing and adopting condition based maintenance practices. In this paper various condition assessment techniques for oil filled transformers are discussed and few case studies are presented.


How to Cite
Kumar Puhan, D., Sharma, R., Meena, K. P., & Nageshwar Rao, B. (2018). Condition Assessment Techniques for Insulation Diagnosis of Oil Filled Power Transformers. Power Research - A Journal of CPRI, 126–131.


  1. Chakravorti S, Dey D, Chatterjee B. Recent trends in the condition monitoring of transformers-theory, implementation and analysis.
  2. IEEE Std. 62-1995 IEEE guide for diagnostic field testing of electric power apparatus-Part1 oil filled transformers, regulators and reactors. IEEE Xplore Digital Library; 1995 Dec 1.
  3. IEC Std. 60076-18, power transformer Part-18: Measurement of frequency response. International Electrotechnical Commission (IEC); 2012 Jul.
  4. Lifetime Evaluation of transformers. CIGRE Working Group 12.09; 1993.
  5. Pradhan MK, Ramu TS. On estimation of elapsed life of oil-immeresed power transformers. IEEE Transactions on Power Delivery. 2005; 20(3):1962–9.

Most read articles by the same author(s)

1 2 > >>