New Method to Identify Sympathetic Inrush in Transformer Based on Hilbert Huang Transform


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Sympathetic inrush may cause the mal-operation of differential protection. Aiming at this problem, based on the characteristic that sympathetic inrush contains a lot of aperiodic component and high harmonics, this paper proposes to use Hilbert Huang transform to identify sympathetic inrush. Firstly, the mathematical model of sympathetic inrush is established to analyze its characteristic. Then Hilbert transform is used to obtain harmonic contents of sympathetic inrush and internal fault current. According to the proportion of fundamental to current, sympathetic current can be identified and differential protection can be blocked. The simulation results show that this method has better reliability and sensitivity than the second harmonic restraint scheme. Besides, it has a good ability against TA saturation.



Edited by:

Mohamed Othman




M. F. Gong et al., "New Method to Identify Sympathetic Inrush in Transformer Based on Hilbert Huang Transform", Applied Mechanics and Materials, Vols. 229-231, pp. 863-867, 2012

Online since:

November 2012




[1] SUN Xiangfei, SHU Hongchun, YU Jilai. Comparison of sympathetic inrush influence on differential protection between parallel and series transformers, Electric Power Automation Equipment, vol 29, pp.36-41, (2009).

[2] YUAN Yu-bo, LU Yu-ping, XU Yang, et al. The Influence and Countermeasure to Transformer Differential Protection of CT Partial Transient Saturation Caused by External Fault Removal, Proceedings of the CSEE, vol 25, pp.12-17, (2005).

[3] Hayward C D. Prolonged Inrush Currents with Parallel Transformer Affect Differential Relaying, AIEE Transactions, vol 60, pp.1096-1101, (1941).


[4] YU Gao-wang, BI Da-qiang, WANG Zhi-guang, et al. Phenomenon of Sympathetic Inrush and Analysis of an Example, Automation of Electric Power Sysmtem, vol 29, pp.20-23, (2005).

[5] Bronzeado H, Brogan P, Yacamini R. Harmonic analysis of transient currents during sympathetic interaction, IEEE Transactions on Power System, vol 11, pp.2051-2056, (1996).


[6] BI Da-qiang, SUN Ye, WANG Xiang-heng, et al. Application of Equivalent Instantaneous Inductance in Nonstaturation Zone to Identify the Sympathetic Inrush in Transformer, Electrical Equipment, vol 9, pp.21-24, (2008).

[7] SHAO De-jun, YIN Xiang-gen, ZHANG Zhe, et al. Method to Identify Transformer Sympathetic Inrush Based on the Fundamental Component Increment, Proceedings of the CSEE, vol 30, pp.77-83, (2010).

[8] GU Jun, ZHENG Tao, XIAO Shi-wu, et al. A New Algorithm Based on Time Differential Method to Identify Sympathetic Inrush of Transformers Connected in Wye-delta Mode, Proceedings of the CSEE, vol 27, pp.6-11, (2007).

[9] BI Da-qiang, WANG Xiang-heng, LI De-jia, et al. Theory Analysis of the Sympathetic Inrush in Operating Transformers, Automation of Electric Power Systems, vol 29, pp.1-8, (2005).

[10] ZHENG Tao, ZHAO Ping. Analysis of Influence Factors of Sympathetic Inrush on Differential Protection and Its Solutions, Automation of Electric Power Systems, vol 33, pp.74-78, (2009).