蒸汽发生器液位控制系统手自动切换的前馈补偿研究

Research on Feedforward Compensation for Steam Generator Level Control System Manual/Automatic Switch

当前蒸汽发生器(SG)液位控制系统手自动切换信号复制回路的设计中,液位控制器运算基准为切换时的汽水失配信号,主给水流量调节阀由手动模式切到自动模式后导致SG液位控制系统失去快速调节给水流量的前馈作用。针对该问题,结合阳江核电厂4号机组SG液位高高跳堆事件,提出了针对手自动切换操作方式和系统设计的2种优化方案。针对操作方式的优化,在主给水流量调节阀投自动前,手动平衡汽水流量;针对系统设计的优化,增加汽水失配判断环节和前馈自动补偿环节。通过SG液位扰动试验证明,所提出的优化方案能有效提高手自动切换后控制系统的调节速度、减小超调量,对核电机组安全运行水平提升有重要贡献。

Based on the current design of the replication loop for the steam generator level control system,after the main feed water flow regulating valve is switched from manual mode to automatic mode,the calculation basis of the level controller is the steam water mismatch signal during switching,which causes the control system to lose the feed-forward function of fast regulating feed water flow.Combined with the HH reactor trip event in the steam generator level of unit 4 in Yangjiang Nuclear Power Plant,two optimization schemes are proposed for the manual/automatic switching operation scheme and systematic design.For the optimization of the operation mode,,before the main feed water flow regulating valve is put into operation automatically,the steam water flow is manually balanced.For the optimization of the systematic design,the steps for the steam water mismatch judgment and the feed-forward compensation are added.Through the liquid level disturbance test of the steam generator in unit 4 of Yangjiang Nuclear Power Plant,it is proved that the optimization scheme can effectively improve the regulating speed of the control system and reduce the overshoot,which has an important contribution to the safe operation level of the unit.