发电机组甩负荷试验二次超速异常分析及解决措施

AbnormalAnalysis and Solution of Secondary Overspeed in Load Rejection Test of Generator Set

针对某火力发电厂660 MW发电机组进行甩负荷性能试验过程中发生二次超速故障进行分析,由OPC控制逻辑原理出发,指出DEH联合启动逻辑里“DEH1-BPLDA”信号复位置0,中调阀接受记忆开度指令,导致阀门开度增大,汽轮机进汽量增加,发生二次超速。因此,提出了逻辑优化解决方案和预防对策。试验证明优化后的DEH逻辑能够有效地避免中调阀开度突增,同时在发电机组甩负荷性能试验时,加强对机组再热压力的控制,也能防止汽轮机发生二次超速,为同类型机组DEH控制逻辑优化提供了参考。

Based on OPC control logic principle, it is pointed out that the complex position of "DEH1-BPLDA" signal in DEH combined startup logic is 0, and the middle control valve accepts the memory opening instruction, which leads to the increase of valve opening and steam intake and second speed limit occurred. Therefore, logical optimization solutions and preventive measures are proposed. The experiment proves that the optimized DEH logic can effectively avoid the sudden increase of the opening of the middle regulating valve, and strengthen the control of the reheat pressure of the generator set during the load rejection performance test, and also prevent the secondary overspeed of the turbine, which provides a reference for the optimization of the DEH control logic of the same type of generator set.