Numerical Algorithm for Power Transformer Protection

  • Park, Chul-Won (Dept. of Electrical Engineering, Wonju National College) ;
  • Suh, Hee-Seok (Dept. of Automation System, Doowon Technical Colleg) ;
  • Shin, Myong-Chul (School of Electrical and Computer Engineering, Sungkyunkwan University)
  • Published : 2004.09.01

Abstract

The most widely used primary protection for the internal fault detection of the power transformer is current ratio differential relaying (CRDR) with harmonic restraint. However, the second harmonic component could be decreased by magnetizing inrush when there have been changes to the material of the iron core or its design methodology. The higher the capacitance of the high voltage status and underground distribution, the more the differential current includes the second harmonic during the occurrence of an internal fault. Therefore, the conventional second harmonic restraint CRDR must be modified. This paper proposes a numerical algorithm for enhanced power transformer protection. This algorithm enables a clear distinction regarding internal faults as well as magnetizing inrush and steady state. It does this by analyzing the RMS fluctuation of terminal voltage, instantaneous value of the differential current, RMS changes, harmonic component analysis of differential current, and analysis of flux-differential slope characteristics. Based on the results of testing with WatATP99 simulation data, the proposed algorithm demonstrated more rapid and reliable performance.

Keywords

References

  1. Korea Electric Power Company, ‘Development of the Integrated Digital Protection and Control System(IDPACS) for Substation’, Final Report, pp. 1-87, 1997.2
  2. IEEE Tutorial Course, ‘Advancements in Microprocessor Based protection and Communication’, Power System Relaying Committee of the IEEE Power Engineering Society, pp. 1-81, 1997
  3. C.W. Park, M.C. Shin, M.H. Kwon, ‘A Daubechies Chul-Won Park, Hee-SeokSuh and Myong-Chul Shin 151 Wavelet Transform Based Criterion Logic Scheme for Discrimination Between Inter-Turn Faults and Magnetizing Inrush in Transformer’, The Trans. of the KIEE Vol. 50A No. 5, pp. 211-217, May, 2001
  4. Sang-Tae Kim, Bo-Geon Jin, Seung-Jae Lee, Sang- Hee Kang, Myeon-Song Choi, Sang-Hyun Yoon, Tae-Sung Lee, Sang-Ki Chung, ‘v, i trend-based protective relaying algorithm for 3-phase power transformer’, Power Engineering Society Summer Meeting, 2001. IEEE, Volume: 1, July pp. 605-610
  5. M.A. Rahman, B. So, M.R. Zaman and M.A. Hoque, ‘Testing of Algorithms for a Stand-Alone Digital Relay for Power Transformer’, IEEE Trans. on PWRD., Vol.13, No.2, pp. 374-385, April, 1998
  6. C.W. Park, J.S. Park, M.C. Shin et al., ‘A Study on Design of IED for Power Transformer’, Proceedings of the KIEE Summer Annual Conference 2003, pp. 268-270, July 2003
  7. Alexander, R.L., ‘Intelligent electronic device (IED) technology SCADA and 3$\phi$ metering’, Rural Electric Power Conference, 2002, pp. C6-C6_3, IEEE 2002
  8. C.W. Park, M.C. Shin, J.H. Kim, ‘Fuzzy Logic- Based Relaying for Large Power Transformer Protection’, IEEE Trans. on PWRD., Vol.18, No.3, pp.718-724, July 2003
  9. A.T. Johns, S.K. Salman, ‘Digital Protection for Power System’, IEEE POWER SERIES 15, Peter Peregrinus Ltd., pp. 183-187, 1995
  10. C.W. Park, M.C. Shin, ‘Advanced Protective Relaying Algorithm by Flux-Differential Current Slope Characteristic for Power Transformer’, The Trans. of the KIEE Vol. 53A No. 7, pp. 382-388, July, 2004
  11. Patrick Bastard, Pierre Bertand, Michel Meunier, ‘A Transformer Model for Winding Fault Studies’, IEEE Trans. on PWRD., Vol.9, No.2, pp. 690-699, April 1994
  12. Chul-Won Park, Kyung-Jae Ha, ‘EMTP Modeling and Fault Analysis of Power Transformer’, KIEE 2003 Annual Kangwon Conference, pp. 1-6, Dec. 2003