Simulation Model for Assessing Operational Performance of Current Transformers


Article Preview

In determining the correct operation of relays of a protection scheme, proper representation of instrument transformers and their behavior in conditions where there can be saturation, is very critical. The main objective of this paper is to develop simulation model for assessing the operational performance of Current Transformer (CT). In order to test the validity of the developed model, three cases of CT operational conditions were considered, with data collected from Gombe, 330/132/33kV PHCN substation. The simulation results revealed various configuration performance responses that could affect relay protective schemes to different degrees. The CT responses revealed that the secondary current and voltage were distorted when the core flux linkages exceeded the set 9.2 pu saturation limit. It is concluded that the model developed for the CT of interest yield satisfactory results.



Advanced Materials Research (Volumes 18-19)

Edited by:

Prof. A.O. Akii Ibhadode




I. Sule, "Simulation Model for Assessing Operational Performance of Current Transformers ", Advanced Materials Research, Vols. 18-19, pp. 71-77, 2007

Online since:

June 2007





[1] M. Kezunovic, C. W. Fromen, and S. L Nilson: Digital Models of Coupling Capacitor Voltage Transformers for Potential Relay Transient Studies. IEEE Transactions on Delivery, Vol. 7, No. 4, October, (1992).


[2] L. A. Kojovic, CT Modeling Techniques for Relay Protection System Transient Studies. International Conference on Power Systems - IPST 2003 in New Orleans, USA, (2003).

[3] B. Kasztenny, D. Sharples, V. Asaro and M. Pozzuli: Distance Relay and Capacitive Voltage Transformer - Balancing Speed and Transient Overreach Annual RelayConference for Protective Relay Engineers, Canada, 11 th -13th April, (2000).

[4] MATLAB 6. 5. 0. 18091 3a Release 13, The Language for Technical Computing, Version 6. 5. 0. 18091 3a Release 13, The Mathworks Inc., USA, 18 th June, (2002).

[5] J. R. Marti, L. R. Linares and H. W. Dommel: Current Transformers and CouplingCapacitor Voltage Transformers in Real- Time Simulations. IEEE Transactions on Power Delivery. Vol. 12, No. 1, January, (1997).


[6] G. Sybille, P. Brunelle, P. Giroux, S. Casoria, R. Gognon, I. Kamwa, R. Roussel, R. Champagne, L. Dassaint and H. Lehuy: SimPowerSystem For use with Simulink, The Mathworks, User's Guide, Version 3, Hydro Québec, TransÉnergy Technologies, 1998- (2003).

[7] B. Ram and D.N. Vishwakarma: Power System Protection and Switchgear, Tata McGrawHill Publishing Co. Ltd., (1997).

[8] F. Wen, Y. Ni and F. F. Wu: Modern Power System Protection - Current and Voltage Transformer Specification and Steady State Performances, Department of Electrical Engineering, Hong Kong Polytechnic University. www. ll. poly. edu. hk/staff/eekkli/msc/lect/ch3_CVT-I. pdf, (2002).

[9] E.W. Golding and F.C. Widdis: Electrical Measurements and Measuring Instruments, Wheelers, London, (1962).

[10] N. X. Ashton: Power System Protection: Principles and Components-Protec17tive Transformers, The Electrical Engineering Training Association, McDonald and Co. Publishing Ltd., Vol. 1, pp.229-306, (2002).

[11] Information on http/www. ee. uidaho. edu/ee/power/EE524/Lectures/L33/tranformers. pdf.

[12] A. Wright and C. Christopolous: Electrical Power System Protection, Chapman and Hall, London, (1993).

[13] D. Angell, R. Spacck and T. Brown, (2003). Instrument Transformers, IPCo.

[14] J.M. Vanderleck, D.W. Allen, J. Berdy, C.F. Buke, S.R. Hayden, G.D. Kotheimer, H.H. Leech, A. Paullow, G.D. Rockefeller, V.N. Stewart, A.H. Summers, and C.A. Woods: Transient Response of Current Transformers, A Summary Report, IEEE on PAS, Vol. 96, No. 6, Nov. /Dec., (1977).

[15] ALSTOM, Transmission & Distribution Energy Automation & Information- CT and CVT Requirements for protection, 2-week Analysis & Protection of Power Systems (APPS) Course for NEPA Nigeria, 17 th - 27th November, (2003).

[16] S.H. Horowitz and A.G. Phadke: Power System Relaying, John Willey & co., Inc., New York, (1993).