Document Type : Applied paper


Department of Electrical Engineering, University of Zanjan, Zanjan, Iran‎


The Lightning Impulse (LI) test is performed on newly manufactured power transformers as a routine Factory Acceptance Test (FAT). A well-known Marx Impulse Generator (MIG) is utilized in this test. The setting of the MIG can be changed to obtain standard LI wave shape. Since various power transformers may have windings with dissimilar designs, different MIG settings may be required for each transformer. The accurate computer simulation of the LI test circuit can give help in finding the optimum setting of the MIG. The Frequency Response (FR) of the power transformer impedance is required in such simulations. Similarly, the transformer FR is required in calculating the Transient Recovery Voltage (TRV) across the contacts of the Circuit Breakers (CB) in the case of the Transformer Limited Fault (TLF). The accurate calculation of such TRVs has a great importance in selecting the proper rating for CBs. The FR of the transformer can be measured directly with network analyzers or some other conventional test instruments. However, performing an additional test to obtain the transformer FR imposes extra cost and efforts. Alternatively, it can be achieved by using the routine LI test results which is readily available. Fortunately in both mentioned applications similar connections are required for transformer terminals. In this paper, the procedure to extract the transformer FR using the LI test results is presented. Then, the validity of such extracted FRs is investigated by comparing them with the ones measured by conventional test instruments. As an innovation, the extracted transformer FRs are used in the LI test circuit simulation and the accuracy of the method is examined by experimental works. Moreover, the application of the extracted FR in TLF TRV calculation is investigated as well. The validity of the all presented theoretical concepts are evaluated using the experimental test results on a real large power transformer.


  1. R. Mirzaei, “A simple fast and accurate simulation method for power transformer lightning impulse test”, IEEE Trans. Power Del., vol. 34, pp. 1151-60, 2019.
  2. R. Mirzaei, F. Bayat, K. Miralikhani, “A semi-analytic approach for determining marx generator optimum setup during power transformers factory test”, IEEE Trans. Power Del., vol. 36, pp. 10-18, 2021.
  3. Samarawickrama et al., “Impulse generator optimum setup for transient testing of transformers using frequency-response analysis and genetic algorithm”, IEEE Trans. Power Del., vol. 30, pp. 1949-57, 2015.
  4. Hribernik, L. Graber, J. Brunke, “Inherent transient recovery voltage of power transformers – a model-based determination procedure”, IEEE Trans. Power Del., vol. 21, pp. 129-34, 2006.
  5. Ito et al., “Study on transient recovery voltages for transformer-limited faults”, IEEE Trans. Power Del., vol. 29, pp. 2375-84, 2014.
  6. Rahimpour et al., “Transfer function method to diagnose axial displacement and radial deformation of transformer windings”, IEEE Trans. Power Del., vol. 18, pp. 493-505, 2003.
  7. Akbari et al., “Transfer function-based partial discharge localization in power transformers: A feasibility study”, IEEE Elec. Ins. Mag., vol. 18, pp. 33-42, 2002.
  8. IEEE Guide for the Application and Interpretation of Frequency Response Analysis for Oil-Immersed Transformers, C57.149-2012.
  9. IEC60076-18, Measurement of frequency response, 2012.
  10. Malewski, B. Poulin, “Digital monitoring technique for HV impulse tests”, IEEE Trans. Power App. Syst., vol. 104, pp. 3108-16, 1985.
  11. Wang, A. Vandermaar, K. Srivastava, “Condition monitoring of transformers in service by the low voltage impulse test method”, 11-th Int. Symp. High Vol. Eng., London, England, 1999.
  12. Leibfried, K. Feser, “Monitoring of power transformers using the transfer function method”, IEEE Trans. Power Del., vol.14, pp. 1333-41, 1999.
  13. Hanique, “A transfer function is a reliable tool for comparison of full and chopped lightning impulse tests”, IEEE Trans. Power Del., vol.9, pp. 1261-66, 1994.
  14. Okabe et al., “Development of high frequency circuit model for oil-immersed power transformers and its application for lightning surge analysis”, IEEE Trans. Diel. Elec. Ins., vol. 18, pp. 541-52, 2011.
  15. Vecchio et al., “Determining ideal impulse generator settings from a generator–transformer circuit model”, IEEE Trans. Power Del., vol. 17, pp. 42-8, 2002.
  16. Gustavsen, “Wide band modeling of power transformers”, IEEE Trans. Power Del., vol. 19, pp. 414-22, 2004.
  17. IEC60076-3, Power Transformers-Part 3: Insulation levels, dielectric tests and external clearances in air, 2000.
  18. Harner, J. Rodriguez, “Transient recovery voltages associated with power-system, three-phase transformer secondary faults”, IEEE Trans. Power App. Syst., vol. 91, pp. 1887-96, 1972.
  19. Harner, “Distribution system recovery voltage characteristics: I-transformer secondary-fault recovery voltage investigation”, IEEE Trans. Power App. Syst., vol. 87, pp. 463-87, 1968.
  20. Myomin et al., “Investigation of EMTP transformer model for TRV calculation after fault current interrupting by using FRA measurement”, IEEE Power Energy Soc. T&D, New Orleans, LA, USA, 2010.
  21. Koshizuka et al., “TRV under transformer limited fault condition and frequency-dependent transformer model”, IEEE Power Energy Soc. Gen. Meet., San Diego, CA, 2011.
  22. Teymouri et al., “A comparative review of different transformer modelling methods in TRV studies in case of transformer limited faults”, Eng. Sci. Tech. Int. J., vol. 22, pp. 600-9, 2019.
  23. Steurer, W. Hribernik, J. Brunke, “Calculating the transient recovery voltage associated with clearing transformer determined faults by means of frequency response analysis”, IEEE Trans. Power Del., vol. 19, pp. 168-73, 2004.
  24. John, P. Kuffel, High voltage engineering fundamentals, 2000.
  25. Smeets et al., “Switching in electrical transmission and distribution systems”, Willey, 2015.
  26. Parrott, “A review of transformer TRV conditions”, CIGRE WG 13.05, ELECTRA, no. 102, pp 87-118.
  27. Garzon, High voltage circuit breakers, design and applications, 2nd ed., Marcel Dekker Inc., 2002, chapter 3, Basel, New York.
  28. Schon, High Impulse Voltage and Current Measurement Techniques, Fundamentals Measuring Instruments Measuring Methods, 1st ed., 2013, chapter 3, Springer, Switzerland.