A new current differential protection scheme for two-terminal transmission lines

Min Zhang, Xinzhou Dong, Z. Q. Bo, B. R.J. Caunce, A. Klimek

Research output: Chapter in Book/Report/Conference proceedingConference contribution book

26 Citations (Scopus)


This paper describes a new current differential relay. A current differential plane is presented firstly to depict different system statuses. Two traditional current differential protection schemes are discussed by plotting their operating and restraint region in the current-differential plane. A relay characteristic with more appropriate operating and restraint region is plotted in the plane by analyzing the tolerances a current differential relay has. Based on the analysis, a new scheme of current differential protection is designed. It is tolerant of channel delay asymmetry, power system impedance nonhomogeneity and CT saturation. Finally we prove the relay performance using simulations. It enhances current differential relay performance without a significant increase in cost.

Original languageEnglish
Title of host publication2007 IEEE Power Engineering Society General Meeting, PES
Number of pages6
Publication statusPublished - 1 Dec 2007
Event2007 IEEE Power Engineering Society General Meeting, PES - Tampa, FL, United States
Duration: 24 Jun 200728 Jun 2007


Conference2007 IEEE Power Engineering Society General Meeting, PES
Country/TerritoryUnited States
CityTampa, FL


  • current differential plane
  • differential protection
  • operating region
  • restraint region
  • power transmission lines
  • power transmission protection
  • relay protection
  • tolerance analysis
  • transmission lines

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