一起一次调频设置不当引致机组跳闸事故分析

Analysis About a Turbine Trip Accident Caused by the Setting of Inappropriate Parameters in Primary Frequency Regulation

对OVATION分散控制系统组成的汽轮机数字电液调节系统(DEH)中的目标值、设定值、GV主控指令及一次调频等逻辑回路进行了剖析。当一次调频回路参数设置不当,目标值的跟踪会叠加上一个额外的数值,由于跟踪回路的循环累加运算,对汽轮机调门造成了极大的扰动,威胁机组安全运行。针对此问题,以一台600MW超临界机组为例,讲述一起DEH投遥控时引起调门波动,最后造成机组跳闸的经过,对调门波动的原因进行了分析,提出预防措施。

The paper analyzes the logic circuits of the turbine Digital Electro- Hydraulic control system （DEH） composed of the OVATION distributed control system., which include the target, setpoint, GV master, and primary frequency regulation etc. When the setting of parameters in primary frequency regulation is inappropriate, the tracking loop of target value will be superimposed an additional value. Because of the cycle cumulative operation of the tracking loop, it causes great disturbance to the turbine governing valve, which will threaten safe operation of unit. By taking this problem of a 600MW supercritical generating unit as an example, this paper introduces that putting DEH to remote control mode caused fluctuations to the governing valve of turbine, The paper also analyzes the reasons of fluctuations to the governing valve, and puts forward some preventive measures.