CT Saturation Detection with Calculation of Instantaneous Impedance of Magnetic Branch Using FILT

Document Type : Research Paper

Authors

Abstract

Accurate indiscrimination of CT saturation can be caused mal-operation of protection systems. Due to nonlinear and loss characteristic behavior of CTs, it is necessary to use a numerical method to detect CT saturation, accurately. In this paper a new method has been presented to determine the CT saturation. In proposed method, the core loss of CT and instantaneous inductance of magnetic core have been modeled by linear and nonlinear resistances and Jiles Atherton model, respectively. Then the instantaneous impedance of magnetic branches has been calculated by Fast Inverse Laplace Transform (FILT). This algorithm has been implemented to Matlab and PSCAD/EMTDC softwares. Also, impact of different parameters such as type of fault, residual flux, fault initial angle, DC offset and etc. have been evaluated. In comparison with previous researches, simulation results show this algorithm have the proper accuracy, speed and reliability.

Keywords


[1]. Y. C. Kang, S. H. Ok, and S. H. Kang, "A CT Saturation Detection Algorithm", IEEE Trans. Power Del., Vol.
19, No. 1, Jan.2004, pp. 78–85.
[2]. Dashti, H., Sanaye-Pasand M., Davarpanah, M, "Fast and Reliable CT Saturation Detection Using a Combined
Method", IEEE Trans. On Power Delivery, Vol. 24, No. 4, Oct. 2013, pp. 2254-2263.
[3]. E. M. dos Santos, G. Cardoso, Jr., P. E. Farias, and A. P. de Morais, "CT Saturation Detection Based on the
Distance Between Consecutive Points in the Plans Formed by the Secondary Current Samples and Their
Difference-Functions", IEEE Trans. On Power Delivery, Vol. 28, No. 1, Jan 2013, pp. 29 – 37.
[4]. Dong-Gyu Lee, Sung-Rok Yoo and Sang-Hee Kang, "A Phasor Estimation Algorithm during CT Saturation",
IEEE Conference PowerTech, Jun. 2011, pp. 19-23.
[5]. Shun-Tsai Liu, Sy-Ruen Huang, Hung-Wei Chen, Ting-Yen Hsien,“Current Transformer Module Basing the
Jiles-Atherton Hysteresis Model in EMTP/ATP Simulation”, International Power Engineering
Conference (IPEC), 2005, pp. 653 - 656.
[6]. Shun-Tsai Liu, Sy-Ruen Huang, Hung-Wei Chen, "Using TACS Functions Within EMTP to Set Up Current-
Transformer Model Based on the Jiles–Atherton Theory of Ferromagnetic Hysteresis", IEEE Trans. on
Power Delivery, Vol. 22, No. 4, Oct. 2007, pp. 2222 – 2227.
[7]. Y. C. Kang, J. K. Park, S. H. Kang, A. T. Johns, and R. K. Aggarwal, "An Algorithm for Compensating
Secondary Currents of Current Transformers", IEEE Trans. Power Del., Vol. 12, No. 1, Jan.1997, pp.
116–124.
[8]. Y. C. Kang, S. H. Ok, and S. H. Kang, "A CT Saturation Detection Algorithm", IEEE Trans. Power Del., Vol.
19, No. 1, Jan.2004, pp. 78–85.
[9]. Y. C. Kang, S. H. Ok, S. H. Kang, and P. A. Crossley, "Design and Evaluation of an Algorithm for Detecting
Current Transformer Saturation", Proc. Inst. Elect.. Eng., Gen., Transm. Distrib, Vol. 151, No. 1, Jan.
2004, pp. 27–35.
[10]. C. Fernandez, "An Impedance-Based CT Saturation Detection Algorithm for Busbar Differential
Protection", IEEE Trans. Power Del., Vol. 16, No.4, Oct. 2001, pp. 468–472,.
[11]. D.Y. Shi, J. Buse, Q.H. Wub, C.X. Guo, "Current Transformer Saturation Compensation Based on a Partial
Nonlinear Model", Electric Power Systems Research, Vol. 97, Apr. 2013, pp. 34-40.
[12]. T. Hosono, "Numerical inversion of Laplace Transform and Some Applications to Wave Optics", Radio
sci., Vol. 16, No. 6, Nov. 1981, pp. 1015-1019.
[13]. N. G. Chothani, Vimal Sharma, “A New Method for CT Saturation Detection using Secondary Current
Envelope Detector”, International Conference on Recent Developments in Control, Automation and
Power Engineering (RDCAPE), 2015, pp. 1-6.
[14]. Sang-Hee Kang, Min-Soo Kim, Soon-Ryul Nam, Jonathan H. Shin†, Jong-Jin Jung, “A CT Saturation
Detection Algorithm Based on Wavelet Transformation”, 12th IET International Conference on
Developments in Power System Protection (DPSP 2014), pp. 1-4.