Abstract: Selective catalytic reduction (SCR) technology is widely used for flue gas denitration of thermal power plants. The SCR denitration system is very complex and SCR system has the characteristics of large inertia, dead-time, strong disturbance and uncertainty. So, it is almost impossible to achieve precise control of the amount of ammonia injection by the traditional PID control scheme. In this paper, a robust disturbance rejection control method for SCR denitration system is presented. Based on the design of robust PID controller, robust time-delay filter is used to suppress the strong disturbance of the system. The simulation results show that the addition of robust time-delay filter improves the dynamic performance of the system and makes the system has outstanding disturbance rejection performance. The scheme proposed in this paper has simple structure, easy parameter tuning and good robustness. It is worth popularizing in engineering.

Key words: SCR, flue gas denitration, robust PID, time-delay filter, disturbance rejection, optimizing tuning

摘要： 选择性催化还原(Selective Catalytic Reduction，SCR)技术是目前火电厂广泛采用的烟气脱硝方法，SCR脱硝系统反应过程复杂，具有大惯性、大迟延、强扰动和不确定性等特点，传统的PID控制无法实现喷氨量的精确控制。因此提出了一种SCR脱硝系统的鲁棒抗扰动控制方法，在设计鲁棒PID控制器的基础上，利用鲁棒时滞滤波器来达到抑制系统强干扰的目的。仿真实验表明，鲁棒时滞滤波器的加入改善了系统的动态性能，同时使得系统具有突出的抗干扰能力。该方法结构简单、整定方便、鲁棒性好，值得在工程应用中推广。 

关键词: SCR, 烟气脱硝, 鲁棒PID, 时滞滤波, 抗干扰, 优化整定