The Protective Co-ordination between Low-Voltage Circuit-Breaker

저압차단기기의 보호협조

  • Park, S.C. (Electro Technology R&D Center, LG Industrial systems) ;
  • Oh, J.S. (Electro Technology R&D Center, LG Industrial systems) ;
  • Lee, B.W. (Electro Technology R&D Center, LG Industrial systems) ;
  • Ryu, M.J. (Electro Technology R&D Center, LG Industrial systems) ;
  • Seo, J.M. (Electro Technology R&D Center, LG Industrial systems)
  • 박성찬 (LG산전 전력연구소 전력기기연구팀) ;
  • 오준식 (LG산전 전력연구소 전력기기연구팀) ;
  • 이방욱 (LG산전 전력연구소 전력기기연구팀) ;
  • 유만종 (LG산전 전력연구소 전력기기연구팀) ;
  • 서정민 (LG산전 전력연구소 전력기기연구팀)
  • Published : 2001.11.16

Abstract

In an electrical network, electrical power are transmitted by a various of protection, isolation and control electric circuit devices. This thesis deals with the protection function between circuit-breakers. The protective coordination concerns the behaviour of two devices placed in series in an electrical network, with a short-circuit downstream circuit-breaker. It has two basic principles: First, discrimination which is an increasing requirement of low voltage electrical distribution systems. Second, which is less well known: cascading, which consists of installing a device, whose breaking capacity is less than the three-phase short-circuit current at its terminals and helped by main circuit-breaker. The important advantage of cascading is to be able to install at a branch circuit-breaker of a lesser performance without endangering the safety of the installation for more economical usage. To determine and guarantee co-ordination between two circuit breakers, it is necessary to carry out a theoretical approach, first, and then confirm the results by means of standard tests. This is illustrated in appendix A of IEC 947-2.

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