汽轮机抽汽逆止门异常关闭原因分析及处理

针对某电厂l、2号发电机组在运行中频繁发“发电机跳闸”报警，引起机组热工保护PLC动作，使抽汽逆止门关闭的问题进行分析，提出改进措施。分析结果表明：故障产生的原因是保护电源受到干扰，干扰信号通过J1、J3长线路上的等效电容进入到PLC中，引起了“发电机跳闸”保护误动。对原发电机跳闸信号线路进行改进后，抽汽逆止门异常关闭的现象不再发生。

Cause analysis and treatment of extraction check valve abnormal closing for steam turbine

Aiming at the problem of No. 1 and No.2 units in a power plant frequently occurring gen- erator trip in operation, causing programmable logic controller （PLC） action, bringing on extraction check valve closing, to make analysis. The analysis result shows that the causes of the problem are power source of protection device get disturbance, the disturbance signal come into PLC through equivalent capacity on J 1 and J3 lines, lead to protection device misoperation of generator trip. Afeter improving trip signal line of the original generator, the phenomenon of extraction check valve abnor- mal closing have never appearance.