中国电机工程学会2015年年会论文集
一起发电机差动保护CT断线事故的原因分析
丁建伟、王天宝、王畅宇、范斯苑
(山西京玉发电有限责任公司 山西省右玉县 037200)
Cause analysis of CT wire break in generator differential protection
Ding Jianwei, Wang Tianbao, Wang Changyu, Fansiyuan (Shanxi Jing Yu Power Co., Ltd. Shanxi Youyu 037200)
ABSTRACT: Generator differential protection CT disconnection occurs in a power plant unit #2 normal operation process. #2 machine protection group a screen (NARI RCS-985) generator differential protection action, the No. 2 main transformer high voltage side of the circuit breaker is tripped, death magnetic switch, #2 6kV21, 6kV22 working power supply into line switch, close the main stop valve and start the factory power supply switch. Unit stop. After the equipment connection check, the differential calculation analysis and the spot record the wave pattern contrast, the abnormal situation produces the reason thoroughly to find out. In this paper, the process of abnormal situation analysis, problem solving, analysis of the consequences of generator CT disconnection,
for
professional
and
technical
personnel analysis, relay setting value setting, to solve the problem has a good reference.
KEY WORD: Relay protection; CT disconnection; differential protection; generator; CT;
摘要:某发电公司#2机组正常运行过程中发生了发电机差动保护CT断线，#2机发变组保护A屏（南瑞RCS-985） “发电机差动保护”动作，跳开2号主变高压侧断路器、灭磁开关、#2机6kV21、6kV22段工作电源进线开关、关闭主汽门并启动厂用电切换。机组停机。经过设备接线检查、差动计算分析与现场录波图形对比，将异常情况产生原因彻底查清。本文通过异常情况分析、问题解决的过程，分析了发电机CT断线的后果，对于专业技术人员分析、继电保护定值整定、解决检查同类问题有很好的借鉴作用。
关键词：继电保护；CT断线；差动保护；发电机；CT；
分，发电机的安全运行对保证电力系统的正常工作和电能质量起着决定性的作用，发电机差动保护作为发电机定子绕组相间短路故障的主保护已广泛在电力系统中应用。CT断线：正常运行时，无论是机端侧还是中性点侧出现CT断线，满足CT断线判据时，保护装置发“CT断线”告警。并由控制字决定是否闭锁比率差动保护。 </