Proceedings of the KIEE Conference (대한전기학회:학술대회논문집)

The Korean Institute of Electrical Engineers (대한전기학회)
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A Current Differential Relaying Algorithm for Power Transformers Using the Difference of a Differential Current

차전류의 차분을 이용한 변압기 보호용 전류차동 계전방식

  • Kang, Y.C. (Chonbuk National University, NPT Center) ;
  • Kim, D.S. (Chonbuk National University, NPT Center) ;
  • Lee, B.E. (Chonbuk National University, NPT Center) ;
  • Kim, E.S. (Chonbuk National University, NPT Center) ;
  • Won, S.H. (Chonbuk National University, NPT Center)
  • 강용철 (전북대학교 전자정보 공학부, 차세대전력기술연구센터) ;
  • 김대성 (전북대학교 전자정보 공학부, 차세대전력기술연구센터) ;
  • 이병은 (전북대학교 전자정보 공학부, 차세대전력기술연구센터) ;
  • 김은숙 (전북대학교 전자정보 공학부, 차세대전력기술연구센터) ;
  • 원성호 (전북대학교 전자정보 공학부, 차세대전력기술연구센터)
  • Published : 2002.11.15
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Abstract

This paper proposes a current differential relaying algorithm for power transformers using the third difference function of a differential current. The algorithm observes the instants when the wave-shape of the differential current is changed due to the change of the magnetization inductance. If the value of the third difference is bigger than the threshold, the output of a current differential relay is blocked for a cycle. In the cases of magnetic inrush and overexcitation, the blocking signal is maintained: however, for internal faults, reset in a cycle. The test results clearly show that the algorithm successfully distinguishes internal faults from magnetizing inrush.

Keywords