Discrimination of Three-Phase Three-Limb Transformer Inrush Current Based on Characteristics of Instantaneous Excitation Inductances

Abstract:

Existing methods utilizing excitation inductances to discriminate inrush current and internal fault of transformer are all derived from the singe-phase transformer circuit model, yet there are no discussions considering the widely used three-phase three-limb transformers. In view of this question, the mathematical model of three-phase three-limb transformer based on the characteristics of its magnetic equivalent circuit is established, through which the excitation inductances of the three-phase three-limb transformer can be calculated. The calculated excitation inductances have definite physical meanings and can reflect the saturation state of the transformer core under inrush condition. Analysis of the circuit model demonstrates that the delta circulating current is not the excitation current of three-phase three-limb transformer, so the proposed method can be used to the transformers with delta connection directly. The proposed method has been verified by electromagnetic transients program including direct current (EMTDC) simulations, simulation results show that the calculated excitation inductances have different characteristics under inrush and internal fault conditions, and can be applied to identify the inrush current of three-phase three-limb transformer.

• Periodical: Advanced Materials Research (Volumes 433-440)
• Pages: 7267-7274
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.433-440.7267
• Online since: January 2012
• Authors: Suo Nan Jiale, Li Qiang Xu, Zai Bin Jiao, Bin Du
• Keywords: Excitation Inductance, Inrush Current, Relay Protection, Three-Phase Three-Limb Transformer, Wye-Delta Connection

References

[1] Baoming Ge, Anibal T. de Almeida, Qionglin Zheng and P. Xiangheng Wang, An equivalent instantaneous inductance-based technique for discrimination between inrush current and internal faults in power transformers, IEEE Transactions on Power Delivery, vol. 20, Oct. 2001, pp.2473-2482.

DOI: 10.1109/tpwrd.2005.855443

[2] Zong Hongliang，Jin Huafeng，Zhu Zhenfei，et al．Transformer inrush detected by the variation of magnetizing impedance[J]．Proceedings of CSEE，2001，21 (7)：91-94(in Chinese).

[3] Zheng Tao, Liu Wanshun，Zhuang Hengjian，et al．A new algorithm based on the distribution of the normalized equivalent instantaneous inductance for the discrimination of inrush[J]．Proceedings of CSEE，2005，25 (23)：47-53(in Chinese).

[4] Kang Xiaoning, He Lu, ，Jiao Zaibin，et al．Distinguishing magnetizing inrush based on characterastics of excitation inductance[J]．Journal of xian jiaotong university，2007，41(10)：1214-1218(in Chinese).

[5] Suonan Jiale, Zaibin Jiao, Guobing Song and Xiaoning Kang, Algorithm to identify the excitation inductance of power transformer with wye-delta connection, IET Electric Power Applications, vol. 3, 2009, pp.1-7.

DOI: 10.1049/iet-epa:20080037

[6] Mohammed Elleuch, A Contribution to the modeling of three phase transformers using reluctances, IEEE Transactions on Magnetics, vol. 32. 1996, pp.335-344.

DOI: 10.1109/20.486517

[7] Bruce A Mork, Dmitry Ishchenko and Don L Stuehm, Hybrid transformer model for transient simulation, IEEE Transactions on Power Delivery, vol. 22. 2007, pp.248-256.

DOI: 10.1109/tpwrd.2006.883000

[8] Luis M R Oliveira and A J Marques Cardoso, A coupled electromagnetic transformer model for the analysis of winding inter-turn short-circuits, IEEE International Symposium on Diagnostics for Electrical Machines，Power Electronics and Drives, 2001, pp.367-374.

[9] W Enright, J Arrillaga and N R Watson, Modelling multi-limb transformers with an electromagenetic transient program, Mathematics and Computers in Simulation, vol. 46. 1998, pp.213-223.

DOI: 10.1016/s0378-4754(97)00136-5

[10] J Arrillage, W Enright and N R Watson, Improved simulation of HVDC converter transformers in electromagnetic transient programs, IEE Proceedings-Generation, vol. 14. 1997, pp.100-106.

DOI: 10.1049/ip-gtd:19970849