交直流串扰引起保护误动的分析及其对策  

Analysis and Countermeasure of Misoperation Caused by AC-DC Interference

作　　者：桂小燕 

机构地区：[1]赣能股份有限公司江西丰城二期发电厂,江西丰城331100

出　　处：《能源研究与管理》2014年第3期49-51,共3页Energy Research and Management

摘　　要：通过对一起发变组保护误动事故的调查分析,发现其直流控制回路的电缆过长,分布电容过大,当交流串入直流系统时,会通过控制电缆的分布电容构成回路,产生电容电流,引起一些动作值较低的灵敏继电器发生误动作,并据此提出了防范措施。通过改进继电保护二次回路,提高非电量保护启动功率,缩短直流控制电缆的长度,避免了此类问题的重复出现。Through the investigation on the accident resulted from generator-transformer unit misoperation, find that the length of the cable in protection loop is too long and the distributing capacitance of the cable is too big. When the severe mutual interference between DC and AC circuits effects as DC grounding, the sudden discharge of distributed capacitance, as a disturbance source, activates the output relay. Countermeasures are suggested, shorten the length of DC control cables, increase the voltage of intermediate output relay and breaker trip coil, avoid the repetition of such problems.

关 键 词：交直流串扰 保护误动 分布电容 控制电缆 直流回路 非电量保护 发变组 

分 类 号：TM774[电气工程—电力系统及自动化]