Title :
A CT saturation detection algorithm using symmetrical components for current differential protection
Author :
Villamagna, Nicholas ; Crossley, Peter A.
Author_Institution :
Sch. of Electr. & Electron. Eng., Queen´´s Univ. of Belfast, UK
Abstract :
A method of symmetrical component analysis for the detection of current-transformer (CT) saturation in a numerical current differential feeder protection relay is presented in this paper. The performance of the differential relay is investigated for various faults on a typical Electro-Magnetic Transients Program/Alternative Transients Program (EMTP/ATP) simulated transmission feeder. The simulator includes the effects of CT saturation. A comparison between simulation and tests conducted on an analog model testbench are also evaluated. The results show a high degree of similarity and illustrate the effect that CT saturation imposes on the sensitivity and stability of the protection scheme. An algorithm is presented that shows significant improvement in sensitivity on internal faults while still maintaining a high level of stability on external faults and nonfault events.
Keywords :
EMTP; current transformers; power transformer protection; power transmission faults; relay protection; alternative transients program simulated transmission feeder; analog model testbench; current differential protection; current transformer saturation detection algorithm; electromagnetic transients program; faults sensitivity; numerical current differential feeder protection relay; symmetrical component analysis; Circuit faults; Current transformers; Detection algorithms; EMTP; Fault currents; Power engineering and energy; Protection; Protective relaying; Stability; Testing; Current-transformer (CT) saturation; gradient; hysteresis data (HYSDAT); rate of change; sliding data window; symmetrical component; testbench;
Journal_Title :
Power Delivery, IEEE Transactions on
DOI :
10.1109/TPWRD.2005.848654
