An Innovative Protective Algorithm for UHV Power Transformer

  • Xiang-li Deng
  • Chuan-qi Wang
  • Zhe Zhang
  • Xiang-gen Yin
Conference paper
Part of the Lecture Notes in Electrical Engineering book series (LNEE, volume 138)


Transformer differential protection is influenced seriously by harmonics in inrush current and the operation time is long. In order to solve this problem, this paper introduces a T-type equivalent model of transformer protection. The parameters of the model can be calculated uniquely and timely at steady state. A new transformer protection algorithm is presented. The algorithm is based on the balanced equations of T-type equivalent model and the variation of the measured excitation inductance. With EMTP simulation tool, a simulation platform for the first UHV power transmission system in China is established. Situations such as energizing, external faults, internal faults and normal operations in the system are covered in the simulation. The operation time of the proposed protective scheme is short and the scheme has high sensitivity.


Inrush current On-line least-squares identification UHV transformer protection Measured excitation inductance 


  1. 1.
    Lui Z (2005) Ultra-high voltage grid, 3rd edn. China Economic Publishing House, BeijingGoogle Scholar
  2. 2.
    He B, Xu X (1998) Protection based on wave comparison. Proc CSEE 18(6):395–398MathSciNetGoogle Scholar
  3. 3.
    Zhang X, He B (2005) A new method to identify inrush current by phasor comparison. Proc CSEE 25(19):43–47Google Scholar
  4. 4.
    Jiao S, Liu W (1999) A novel scheme to discriminate inrush current and fault current base on integrating the waveform. Proc CSEE 19(8):35–38Google Scholar
  5. 5.
    Xu Y, Wang Z, Yang Q (2004) Research on novel transformer protection based on the characteristics of voltage and differential current. Proc CSEE 24(2):61–65Google Scholar
  6. 6.
    Lin X, He Z et al (2001) Discussions on some aspects of sampling value differential current protection. AEPS 10(10):27–33Google Scholar
  7. 7.
    Wang Z, Xu Y, Wang X et al (2003) A novel scheme based on flux restraint theory used in distinguishing inrush currents for UHV transformers. Proc CSEE 23(12):52–58Google Scholar
  8. 8.
    Zong H, Jin H, Zhu Z et al (2001) Transformer inrush detected by the variation of magnetizing impedance. Proc CSEE 21(7):91–94Google Scholar
  9. 9.
    Wang Z, Xu Y, Wang X et al (2003) Study on the novel transformer protection principle based on the transformer model. Proc CSEE 23(12):54–58Google Scholar
  10. 10.
    Suonan J, Jiao Z, Kang X (2008) Algorithm to identify leakage inductances of power transformer with Y-Delta connection. Proc CSEE 28(13):84–90Google Scholar
  11. 11.
    Xiong X, Deng X, You B (1999) Transformer protection using parameter identification method. AEPS 23:18–21Google Scholar
  12. 12.
    Suonan J, Kang X, Song G (2007) Survey on relay protection using parameter identification. Proc CSU-EPSA 19(1):14–20Google Scholar
  13. 13.
    Zeng L, Lin X et al (2010) Modeling and electromagnetic transient simulation of UHV autotransformer. Proc CSEE 30(1):91–97Google Scholar

Copyright information

© Springer-Verlag London Limited  2012

Authors and Affiliations

  • Xiang-li Deng
    • 1
  • Chuan-qi Wang
    • 1
  • Zhe Zhang
    • 1
  • Xiang-gen Yin
    • 1
  1. 1.School of Electrical and Electronics EngineeringHuazhong University of Science and TechnologyWuhanChina

Personalised recommendations