Browse > Article
http://dx.doi.org/10.5370/KIEE.2010.59.8.1360

Distance Relaying Algorithm Using a DFT-based Modified Phasor Estimation Method  

Lee, Dong-Gyu (명지대 차세대전력기술연구센터)
Kang, Sang-Hee (명지대 차세대전력기술연구센터)
Publication Information
The Transactions of The Korean Institute of Electrical Engineers / v.59, no.8, 2010 , pp. 1360-1365 More about this Journal
Abstract
In this paper, we propose a distance relaying algorithm using a Discrete Fourier Transform (DFT)-based modified phasor estimation method to eliminate the adverse influence of exponentially decaying DC offsets. Most distance relays are based on estimating phasors of the voltage and current signals. A DFT is generally used to calculate the phasor of the fundamental frequency component in digital protective relays. However, the output of the DFT contains an error due to exponentially decaying DC offsets. For this reason, distance relays have a tendency to over-reach or under-reach in the presence of DC offset components in a fault current. Therefore, the decaying DC components should be taken into consideration when calculating the phasor of the fundamental frequency component of a relaying signal. The error due to DC offsets in a DFT is calculated and eliminated using the outputs of an even-sample-set DFT and an odd-sample-set DFT, so that the phasor of the fundamental component can be accurately estimated. The performance of the proposed algorithm is evaluated for a-phase to ground faults on a 345 kV, 50 km, simple overhead transmission line. The Electromagnetic Transient Program (EMTP) is used to generate fault signals. The evaluation results indicate that adopting the proposed algorithm in distance relays can effectively suppress the adverse influence of DC offsets.
Keywords
Distance Relay; DC offset; Phasor Estimation; Discrete Fourier Transform;
Citations & Related Records

Times Cited By SCOPUS : 0
연도 인용수 순위
  • Reference
1 Jyh-Cherng Gu and Sun-Li Yu, "Removal of DC offset in current and voltage signals using a novel Fourier filter algorithm," IEEE Trans. Power Delivery, vol. 15, no. 1, pp. 73-79, Jan. 2000.   DOI   ScienceOn
2 Yong Guo, M. Kezunovic, and Deshu Chen, "Simplified algorithms for removal of the effect of exponentially decaying DC offset on the Fourier algorithm," IEEE Trans. Power Delivery, vol. 18, no. 3, pp. 711-717, July 2003.   DOI   ScienceOn
3 Yoon-Sung Cho, Chul-Kyun Lee, Gilsoo Jang, Heung Jae Lee, "An Innovative Decaying DC Component Estimation Algorithm for Digital Relaying," IEEE Trans. Power Delivery, vol. 24, no. 1, pp. 73-78, January 2009.   DOI
4 T. S. Sidhu, X. Zhang, F. Albasri, and M. S. Sachdev, "Discrete -Fourier-transform-based technique for removal of decaying DC offset from phasor estimates," Proc. Inst. Elect. Eng., Gen., Transm. Distrib., vol. 150, no. 6, pp. 745-752, Nov. 2003.   DOI   ScienceOn
5 Sang-Hee Kang, Dong-Gyu Lee, Soon-Ryul Nam, Peter A. Crossley, Yong-Cheol Kang, "Fourier Transform-Based Modified Phasor Estimation Method Immune to the Effect of the DC Offsets," IEEE Trans. Power Delivery, vol. 24, no. 3, pp. 1104-1111, July 2009.   DOI
6 IEEE Std C37.113-1999 IEEE Guide for Protective Relay Applications to Transmission Lines, pp. 55-57
7 G. Benmouyal, "Removal of DC offset in current waveforms using digital mimic filtering," IEEE Trans. Power Delivery, vol. 10, no. 2, pp. 621-630, April 1995.   DOI   ScienceOn
8 Soon-Ryul Nam, Sang-Hee Kang and Jong-Keun Park, "An Analytic Method for Measuring Accurate Fundamental Frequency Components", IEEE Trans. Power Delivery, vol. 17, no. 2, pp. 405-411, April 2002.   DOI   ScienceOn