区外故障引起的发电机功率突降保护误切机动作分析

Analysis of Power Sag Protection Operation Caused by an External Fault

在发电机组甩负荷初始状态时,发电机功率突降保护装置可快速作出判断并安全停机。文中描述了某电厂出线故障引起功率振荡,发电机组功率变送器传变周期与汽轮机数字电液控制系统(DEH)的设定值不匹配,且波形发生畸变,继而造成机组调门误关闭,功率突降保护动作导致跳机的事件,分析了此动作事件成因,并就如何防范与解决大型机组发生类似问题提出了合理化建议和改进思路。

In the initial stage of generator load-shedding, generator power sag protection devices can judge quickly and shut down safely. Power oscillation was caused by a power plant outlet line failure. The transmission cycle of the generator power transmitter was not matched with the set of steam turbine digital electro-hydraulic control system, and the waveform was distorted. In turn, the unit control valve was shut down by mistake, and the action of power sag protection caused the generator- tripping. This paper analyzes the causes of this action and puts forward some suggestions on how to prevent and solve similar problems in large units.