Method for Detection of Saturation of a Current Transformer

전류변성기의 포화 검출을 위한 알고리즘 개발

  • Published : 2009.05.01

Abstract

A Method for detection of saturation of a current transformer(CT) is proposed. The algorithm is initiated when the end point of a saturation period is detected. This detection is achieved by checking the time interval between the adjacent zero-crossing points of the second derivative of the secondary current. Once the end point of the saturation period is detected, the beginning point of the corresponding saturation period is determined by backward examination of the sum of the secondary current from the end point. The performance of the algorithm was evaluated for a-g faults on a 345 kV 100km overhead transmission line. The Electromagnetic Transient Program(EMTP) was used to generate fault current signals for different fault inception angles and different remanent fluxes. The performance evaluation shows that the proposed algorithm successfully detects the saturation period even in the presence of a remanent flux.

Keywords

Current transformer;Detection;saturation;Second derivative;Zero-crossing point

References

  1. Yong-Cheol Kang, Seung-Hun Ok, Sang-Hee Kang, 'A CT saturation detection algorithm,' IEEE Trans. Power Delivery, 2004:78-85 https://doi.org/10.1109/TPWRD.2003.820200
  2. A. G. Phadke and J. S. Thorp, Computer Relaying for Power Systems, Research Studies Press Ltd., 1988
  3. M. Kezunovic, L. Kojovic, A. Abur, C.W. Fromen, and F. Phillips, 'Experimental evaluation of EMTP-based current transformer models for protective relay transient study,' IEEE Trans. Power Delivery, 1994:405 - 413 https://doi.org/10.1109/61.277712
  4. F. Li, Y. Li, R.K. Aggarwal, 'Combined wavelet transform and regression technique for secondary current compensation of current transformers,' Proc . Inst. Elect. Eng., Gen., Transm., Distrib., 2002:497-503 https://doi.org/10.1049/ip-gtd:20020296
  5. Yong Cheol Kang, Ui Jai Lim, Sang-Hee Kang, Peter A. Crossley, 'Compensation of the distortion in the secondary current caused by saturation and remanence in a CT,' IEEE Trans. Power Delivery, 2004:1642 - 1649 https://doi.org/10.1109/TPWRD.2004.835266
  6. G. Hosemann, H. M. Steigerwald, 'Model saturation detector for digital differential protection,' IEEE Trans. Power Delivery, 1993:933-940 https://doi.org/10.1109/61.252620
  7. K.M. EI-Naggar, M.I. Gilany, 'A discrete dynamic filter for detecting and compensating CT saturation,' Electric Power Systems Research, 2007:527 - 533