Engineering-Oriented Modeling and Experimental Research on DC-Biased Transformers

  • Mansheng GuoEmail author


Due to routine preventative maintenance of equipment and operation commissioning of converter station, the direct current (DC) transmission system may operate in a monopolar ground return mode or an unbalanced dipole mode, which may cause a large direct current to flow into the neutral grounded power transformers. The asymmetrical saturation of the core, the loud noise, the serious vibrations, the local loss density concentration, and the local overheating may occur in a DC-biased transformer when the DC is flowing through the transformer winding. In this chapter, the electromagnetic properties of transformer core, the exciting current under DC bias condition, and the harmonic distribution are experimentally investigated based on two sets of verification transformer models. Furthermore, a large-scale numerical analysis of the 3-D electromagnetic fields and the power loss are carried out. The different DC injection tests are also performed on a 500 kV autotransformer to further demonstrate the harmonic characteristic, no-load loss, and noise level under DC bias. Finally, an estimation method of the abilities to withstand the DC bias is proposed.


DC bias Power transformer Magnetic property Experimental research Modeling and simulation 



This work was supported by China Southern Power Grid Co., Ltd. (CSG), the National Natural Science Foundation of China (NSFC) (no.50677016), and the Hebei Natural Science Foundation (no.E2006000772). In this chapter, the numerical simulations were completed by Mansheng Guo and Junjie Zhang, and the experiments were completed by Zhongxiang Li, Lanrong Liu, Deliang Zhang, and other colleagues. The author thanks the relevant leaders of Baobian Electric, including Dongsheng Liu, Qifan Hu, Zhongji Gao, and Cuiping Jiao, for their strong support.


  1. 1.
    P. R. Price, “Geomagnetically induced current effects on transformers,” IEEE Trans. on Power delivery, vol.17, no.4, pp. 1002–1008,2002.CrossRefGoogle Scholar
  2. 2.
    C. Li, “Influence of DC Monopole Operation on AC Transformer,” East China Power, 2005, 1 (33): 36–39.Google Scholar
  3. 3.
    G. Mei, B. Xu, X. Wang, Z. Deng, and C. Liu, “Influence of DC Transmission on Transformers in AC System,” Guangdong Electric Power, 2006,1 (1): 1–7.Google Scholar
  4. 4.
    D. Kuai, D. Wan, and Y. Zou,”Influence of DC Bias on Transformer,” China Power, 2004, 37 (8): 41–43.Google Scholar
  5. 5.
    P. Picher, L. Bolduc, A. Dutil, and V. Q. Pham, “Study of the acceptable DC current limit in core-form power transformers,” IEEE Trans. on Power Delivery, vo.12, no.1, pp. 257–263, 1997.CrossRefGoogle Scholar
  6. 6.
    L. Liu and X. Xie, “Analysis of Abnormal Noise of 500 kV Main Transformer,” High Voltage Technology. 2005, 31 (4): 85–87.Google Scholar
  7. 7.
    D. Kuai, D. Wan, and Y. Zou,”Analysis and Handling of the Impact of Geomagnetically induced Current Upon Electric Network Equipment in DC Transmission,” Power System Automation. 2005,29 (2): 81–82.Google Scholar
  8. 8.
    X. Wang, and B. Xu, “On the Problem of Transformer Bias,” Transformer, 1992,29 (8): 11–14.Google Scholar
  9. 9.
    Z. Ma, “Simulation of Transformer DC Magnetic Biasing,” Guangdong Electric Power. 2004,17 (2): 5–9.Google Scholar
  10. 10.
    L. Zeng, “Impact of HVDC Ground Electrode Current on the Adjacent Power Transformers,” Electric Power Construction, 2004,12 (25): 22–24.Google Scholar
  11. 11.
    L. Zhong, P. Lu, Z. Qiu, H. Cai,”The Influence of Current of DC Earthing Electrode on Directly Grounded Transformer,” High Voltage Technology, 2003, 8 (29): 12–13.Google Scholar
  12. 12.
    C. Shang, “Measure to Decrease the Neutral Current of the AC Transformer in HVDC Ground-Return System”, High Voltage Technology, 2004,30 (11): 52–54.Google Scholar
  13. 13.
    Y. Wang, and S. Liu, “The Measurement of AC Hysteresis Loop with DC Magnetic Biasing,” Magnetic Materials and Devices, 2001,3 (32): 47–50.Google Scholar
  14. 14.
    Y. Yao, “Research on Direct-current Magnetic Bias of Large Power Transformer,” A Dissertation Submitted to Shenyang University of Technology for the Doctoral Degree, 2000.11.Google Scholar
  15. 15.
    X. Li, “Study on the Transformers under DC Bias,” A Dissertation Submitted to Wuhan University for the Doctoral Degree, 2006.3.Google Scholar
  16. 16.
    N.Takasu, T.Oshi, F.Miyawaki, S.Saito, and Y.Fujiwar, “An experimental analysis of DC excitation of transformers by geomagnetically induced currents,” IEEE Trans. on Power Delivery, vol.9, no.2, pp. 1173–1179, 1994.CrossRefGoogle Scholar
  17. 17.
    E.F.Fuchs, Y.You, and D.J.Roesler, “Modeling and simulation, and their validation of three-phase transformer with three legs under DC bias,” IEEE Trans. on Power Delivery, vol.14, no.2, pp. 443–449, 1999.CrossRefGoogle Scholar
  18. 18.
    L.Bolduc, M.Granger, G.Pare, J.Saintonge, and L.Brophy, “Development of DC current-blocking device for transformer neutrals,” IEEE Trans. on Power delivery,vol.20,no.1, pp. 163–168, 2005.CrossRefGoogle Scholar
  19. 19.
    T.Yoshida, M.Nakano, D.Miyagi, K.Fujiwara, and N.Takahashi, “Development of measuring equipment of DC-biased magnetic properties using open type single sheet tester,”, IEEE Trans. on Magn., vol..42, no10, pp. 2846–2848, 2006.Google Scholar
  20. 20.
    M. Guo, G. Mei, et al. “B–H Curve Based on Core and Asymmetric Magnetizing Current in DC-Biased Transformers,” Transactions of China Electrotechnical Society, 2009,24 (5): 46–51.Google Scholar
  21. 21.
    N.Takahashi, T.Sakura and Z.Cheng, “Non-linear analysis of eddy current and hysteresis losses of 3-D stray-field loss model (Problem 21),” IEEE Trans. on Magn., vol.37, no.5, pp. 3672–3675, 2001.CrossRefGoogle Scholar
  22. 22.
    M. Guo, G. Mei,et al. “Simulation Calculation and Test Research on Harmonic Wave in Power Transformer under DC Bias,” Transformer, 2010,47 (12): 28–31.Google Scholar
  23. 23.
    M. Guo, Z.Cheng, et al. “Three Dimensional Magnetic Field Analysis of Single-Phase Three-Limb Power Transformer under Direct Current Bias,” Transformer, 2007,44 (4): 31–35.Google Scholar
  24. 24.
    Z.Cheng, M. Guo, and L. Li, “Eddy Current Loss Analysis and Validation in Electrical Engineering,” (supported by National Natural Science Foundation of China), Higher Education Press, 2001.Google Scholar
  25. 25.
    K. Preis, O. Biro, G. Buchgraber, and I.Ticar, “Thermal-electromagnetic coupling in the finite-element simulation of power transformers,” IEEE Trans. on Magn., vol.42, no.4, pp. 999–1002, 2006.CrossRefGoogle Scholar
  26. 26.
    O. Biro and K. Preis, “An efficient time domain method for nonlinear periodic eddy current problems,” IEEE Trans. on Magn., vol.42, no.4, 2006, pp. 695–698.CrossRefGoogle Scholar
  27. 27.
    Z. Cheng, R. Hao, N. Takahashi, Q. Hu and C. Fan, “Engineering-oriented benchmarking of Problem 21 family and experimental verification,” IEEE Trans. on Magn., vol. 40, no.2, pp. 1394–1397, 2004.CrossRefGoogle Scholar
  28. 28.
    Z. Cheng, N. Takahashi, S. Yang, T. Asano, Q. Hu, S. Gao, X. Ren, H. Yang, L. Liu and L. Gou, “Loss spectrum and electromagnetic Behavior of Problem 21 family,” IEEE Trans. on Magn., vol.42, no.4, pp. 1467–1470, 2006.Google Scholar
  29. 29.
    Z. Cheng, N. Takahashi, S. Yang, C. Fan, et al, “Eddy Current and loss analysis of multi-steel configuration and validation,” IEEE Trans. on Magn., vol. 43, no.4, 2007, pp. 1737–1740.CrossRefGoogle Scholar
  30. 30.
    M. Guo, G. Mei, X. Zhang, et al, “Calculation of Losses in Single-Phase Three-Limb Power Transformer under DC-Biasing,” Transactions of China Electrotechnical Society, 2010,25 (7): 67–71.Google Scholar

Copyright information

© Science Press, Beijing and Springer Nature Singapore Pte Ltd. 2020

Authors and Affiliations

  1. 1.Design DepartmentBaobian ElectricBaodingChina

Personalised recommendations