900MW超临界机组协调控制及AGC策略的研究与应用

Research and application of coordinated control and AGC strategy in 900 MW supercritical unit

针对外高桥二厂国内首台超临界900MW机组蓄热能力小、全程滑压运行等特点,在理论分析和现场试验的基础上,对原有的协调控制系统(CCS)和自动发电控制(AGC)策略进行了改进和完善,诸如加快变负荷时给水的响应;变负荷时暂时改变主汽压力设定值,以利用锅炉蓄热;燃料、给水超调采用智能判断等,更好地保证了锅炉与汽轮机之间及锅炉燃料与给水之间的协调动作。现场的实际应用表明,改进后的协调控制系统不仅使机组运行更加稳定,而且有效地提高了机组的负荷响应能力。

In view of the features of 900 MW supercritical units in Waigaoqiao No.2 Power Plant such as the limited thermal storage capacity and the whole sliding pressure operation, the control strategy of current Coordinated Control System and AGC was improved and perfected based on the theoretical analysis and on-site experiment. Typically, in order to guarantee the coordination between boiler and turbine efficiently, the following measures were introduced such as accelerating the feedwater response to varying load, changing the setpoints of steam pressure to use boiler storage capacity, intelligent judgment for the overshoot of fuel and feedwate etc. The practical operation shows that the improved control system is of more stability and better response ability to the varying load.