Application Analysis for Loss of Excitation Relay of Generator Protection

Abstract – Recently, the LOE(loss of excitation) incidents are occurred in domestic synchronous generator frequently, the synchronous generator protection system has been much attention for the LOE protection of the incidents that threats synchronous generators and power systems. This paper was showed the characteristics and practices of distance relay that widely used LOE protection relaying in generator. Firstly, the operating characteristics and the impedance locus for LOE of the generator protection were introduced. Even if the conventional simulation program is used for modeling, but it is difficult to implement a LOE modeling and simulation of synchronous generator. So, the LOE relay operation data collected from thermal power plant and nuclear power plant in real fields were analyzed. By reviewing the applications of GE Mho relays, the reliability of LOE for synchronous generator protection in domestic were improved.Key Words : Distance relay, Generator protection, Impedance locus, Loss of excitation, Mho relay, Stability†교신저자 : 강릉원주대학교 전기공학과 교수․공박E-mail : cwpark1@gwnu.ac.kr*한국기술교육대학교 전기전자통신공학부 교수․공박 접수일자 : 2014년 11월 12일수정일자 : 2014년 11월 17일최종완료 : 2014년 11월 19일