A Study on DG Control Strategy and Grid Protection

Abstract:

DG integration reduces the selectivity and sensitivity of grid relay protection. A new control algorithm is proposed. It shows that the negative sequence current will not be affected by DG when the DG is designed as a symmetric three-phase current source. In this case, the negative sequence characteristic can be utilized for grid protection during short-circuit faults. If DGs maximum power capacity is restricted to be lower than total load capacity, DG terminal line-voltage and the negative sequence voltage can be used as the criteria for islanding detection. Then it is possible to cutoff DG in order to fulfill the reclosing requirement. A complicated simulation system is designed using PSCAD/EMTDC program. Different short-circuit faults are simulated to verify the proposals. The test results confirm well with the conclusions.

• Periodical: Applied Mechanics and Materials (Volume 521)
• Pages: 204-212
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.521.204
• Online since: February 2014
• Authors: Xin Chao Wang, Chen Xin Yang
• Keywords: Distributed Generator (DG), Distribution Grid, Negative Sequence Detector, Relay Protection

References

[1] A. Girgis, S. Brahma: Effect of Distributed Generation on Protective Device Coordination in Distribution System[C]. Large Engineering System Conference on Power Eng., 2001: 115-119.

DOI: 10.1109/lescpe.2001.941636

[2] S.K. Salman I.M. Rida: Investigating the impact of embedded generation on relay settings of utilities electrical feeders[C]. IEEE Transactions on Power Delivery, (2001).

DOI: 10.1109/61.915490

[3] J. Wang, X.Y. Li, X.Y. Qiu: Power system research on distributed generation penetration. Automation of Electric Power Systems, 2005, 29 (24): 90-95.

[4] B.H. Zhang: On connection of distributed energy generation to power system [J] . Electric Power Automation Equipment, 2007, 27(12): 1-4.

[5] Z.H. Bie, G.F. Li and X.F. Wang: Review on reliability evaluation of new distribution system with micro-grid. Electric Power Automation Equipment, 2011, 3（1：1-6).

[6] B.H. Zhang, G.H. Li, J. Wang, et al: Electric Power Automation Equipment, 2012, 32(2): 1-8.

[7] W. Huang, J.Y. Lei, X. Xia: Influence of distributed generation on phase to phase short circuit protection in distribution network. Automation of Elec. Power Systems, 2008, 32 (1): 93-97.

[8] F.L. Gao, J.D. Cai: Analysis for distributed generation impacts on current protection in power distribute on networks. . Journal of Elec. Power Sci. and Tech. ，2008，23 (3): 58 - 61.

[9] X. Lin, Y.P. Lu, X.J. Wu: Influence law of distributed generation on relay protection sensitivity [J]. Electric Power Automation Equipment，2009，29（1）：54 - 59.

[10] Y. GAO, R. Bi, W. Yang, Y. Ding: Effect of Distributed Generation on Relay Protection in Distribution System [J]. Power System and Clean Energy, 2009. 4, 25(4): 20-23.

[11] Z. Zeng, H. Yang, R.X. Zhao, et al: Studies on multi-functional grid-connected inverters：an overview［J］. Electric Power Automation Equipment，2012，32（8）：5-15.

[12] X.F. Sun, Q.Q. Lü: Improved PV Control of Grid-Connected Inverter in Low Voltage Micro-Grid [J]. Transactions of China Electro technical Society, 2012, 27(8): 77-84.

[13] Q. Zhang, X.D. Sun, Y.R. Zhong, et al.: Even Harmonic Current Disturbing Method for Islanding Detection in the Distributed Power Generation Systems [J]. Transactions of China Electro-technical Society, 2011, 26(7): 112-118.

[14] F.R. Liu, Y. Kang, S.X. Duan, et al: A Novel Method for Mapping Non-Detection Zone [J]. Transactions of China Electro-technical Society, 2007, 22(10): 167-172.

[15] J.H. Wang, N.L. Tai, K. Song, et al: Penetration level permission of DG in distributed grid for relay protection. Proceedings of the Chinese Society for Electrical Engineering, 2010, 30(22): 37-43.