CAJ | 학술논문

本文分析了一起220kV送出线路单相接地故障跳闸，重合于永久故障后线路跳闸。机组孤网运行情况下机组过速保护动作，全厂交流失压，后机组开机并入系统运行正常。事故显示送出线路故障跳开后，机组进入孤网运行状态，PI调节方式下机组频率振荡，机组高频保护动作导致紧急停机，机组紧急停机造成全厂及孤网交流失压。机组故障仿真及事故过程分析显示，随着孤网运行模式的变换，机组孤网运行判据应相应修正并予以试验。
본문분석료일기220kV송출선로단상접지고장도갑，중합우영구고장후선로도갑。궤조고망운행정황하궤조과속보호동작，전엄교류실압，후궤조개궤병입계통운행정상。사고현시송출선로고장도개후，궤조진입고망운행상태，PI조절방식하궤조빈솔진탕，궤조고빈보호동작도치긴급정궤，궤조긴급정궤조성전엄급고망교류실압。궤조고장방진급사고과정분석현시，수착고망운행모식적변환，궤조고망운행판거응상응수정병여이시험。
In the paper,a single-phase grounding failure tripping on 220kV outgoing line is analyzed,which is overlapped with line tripping after permanent failure.The unit has over-speed protection action under the condition of unit isolated network operation.The whole plant suffers from AC under-voltage.The rear unit is started and incorporated into the system for normal operation.After outgoing line failure tripping is displayed due to accident,the unit enters into isolated network operation state.The unit frequency is fluctuated under PI regulation mode.Unit high frequency protection results in emergency suspension.The whole plant and isolated network suffer from AC under-voltage due to the emergency suspension of unit.Unit failure simulation and accident process analysis show that unit isolated network operation judgment should be correspondingly corrected and tested with the change of isolated network operation mode.