Advanced SearchSearch Tips
A Modified Selective Ground Relay for Ungrounded Distribution Systems
facebook(new window)  Pirnt(new window) E-mail(new window) Excel Download
 Title & Authors
A Modified Selective Ground Relay for Ungrounded Distribution Systems
Nam Soon-Ryul; Kang Sang-Hee; Park Jong-Keun;
  PDF(new window)
Selective ground relays (SGRs) are useful fur distinguishing a faulted feeder from the sound feeders in ungrounded systems. However, they sometimes mis-operate due to human or device errors. Particularly, the reversed polarity of zero-sequence current transducers (ZCTs) is the most frequent cause of mis-operation. This paper presents a modified SGR for reducing the probability of mis-operations caused by the reversed polarity of ZCTs. The modification is achieved by introducing an adaptive time delay, which depends on the magnitude of the zero-sequence current and the phase angle deviation from the reference. The modified SGR was successfully demonstrated on a sample ungrounded system without mis-operation.
Adaptive time delay;mis-operation;phase angle deviation;selective ground relay;ungrounded system;zero-sequence current transducer;
 Cited by
The current limiting effects of a matrix-type SFCL according to the variations of designed parameters in the trigger and current-limiting parts, Physica C: Superconductivity, 2008, 468, 15-20, 2054  crossref(new windwow)
The Characteristic Analysis Between Flux-Coupling and Flux-Lock Type SFCL According to Variations of Turn Ratios, IEEE Transactions on Applied Superconductivity, 2008, 18, 2, 737  crossref(new windwow)
Critical Current Equalization via Neutral Lines in a Transformer-Type SFCL, IEEE Transactions on Applied Superconductivity, 2008, 18, 2, 733  crossref(new windwow)
T. Baldwin. and F. Renovich, 'Analysis of fault locating signals for high-impedance grounded systems,' IEEE Trans. Industry Applications, Vol. 38, no. 3, pp. 810 - 817, May-June 2002 crossref(new window)

Xu Bingyin; Xue Yongduan; Li Jing; and Chen Yu; 'Single phase fault detection technique based on transient current and its application in non-solid grounded network,' in Proceedings of Developments in Power System Protection 2001 Conference, pp. 141 - 144, April 2001

Jun Liang; Zhihao Yun; Feifan Liu; and Yutian Liu; 'A method of fault line detection in distribution systems based on wavelets,' in Proceedings a/Power System Technology 2002 Conference, pp. 2635 2639, Oct. 2002

E. T. B. Gross, 'Sensitive Fault Protection for Transmission Lines and Distribution Feeders,' AIEE Transactions, Vol. 60, pp. 968 - 972, Nov. 1941

AIEE committee Report, 'Sensitive Ground Protection,' AIEE Transactions, Vol. 69, 1950, pp. 473-476

S. Hanninen and M. Lehtonen, 'Method for detection and location of very high resistive earth faults,' European Trans. Electrical Power, vol. 9, no. 5, pp. 285-291, 1999 crossref(new window)

Z.M. Radojevic, V.V. Terzija, and N.B. Djuric, 'Numerical algorithm for overhead lines arcing faults detection and distance and directional protection,' IEEE Trans. Power Delivery, Vol. 15, no. 1, pp. 31 37, Jan. 2000 crossref(new window)

T. Baldwin, F. Renovich, and L.F. Saunders; 'Directional ground-fault indicator for high-resistance grounded systems,' IEEE Trans. Industry Applications, Vol. 39, no. 2, pp. 325 - 332, March-April 2003 crossref(new window)

Standards of Korea Electrical Manufactures Cooperative, KEMC 1120-1996

IEEE standard inverse-time characteristic equations for overcurrent relays, IEEE Std C37 112-1996