SCR脱硝系统的线性自抗扰串级控制研究

Linear Active Disturbance Rejection Cascade Control of SCR Denitration System

目前,选择性催化还原技术（selectivecatalytic reduction,SCR）是我国火力发电厂最广泛采用的脱硝技术。但是,SCR脱硝系统具有大惯性、大延迟和强扰动的特点,常规PID控制方案不能较好地实现SCR脱硝系统的控制。为此,提出将线性自抗扰控制（linearactivedisturbance rejection control,LADRC）应用于SCR脱硝系统的外回路控制中。采用频域分析方法给出典型工业控制对象的线性自抗扰控制器参数调整规律,在此基础上获得其用于SCR脱硝控制系统的LADRC控制参数。频域分析表明采用上述控制方案的控制系统性能强于常规PID串级控制系统。蒙特卡洛仿真结果表明,相比于常规PID串级控制系统,基于线性自抗扰串级控制的SCR脱硝控制具有更强的设定值跟踪能力;当系统存在不确定扰动时,其抗干扰性和鲁棒性也显著加强。

At present, selective catalytic reduction （SCR） is China＇s most widely used thermal power plant out of stock technology. However, the SCR denitration system has the characteristics of large inertia, large delay and strong disturbance, so the conventional PID control scheme cannot realize the optiriaal control of SCR denitration system. In this paper, the linear active disturbance rejection control （LADRC） was applied to the external circuit control of SCR denitration system. The frequency domain analysis method was used to give the LADRC controller parameter adjustment of typical industrial control objects. Based on this, the LADRC control parameters for SCR denitration control system were obtained. The frequency domain analysis shows that the SCR denitration control system with the above control scheme is stronger than the conventional PID cascade control system. Monte Carlo simulation results show that SCR denitration control based on linear auto-disturbance rejection cascade control has stronger set-value tracking ability compared with conventional PID cascade control system, and when the system has uncertain disturbance, its anti-interference and robustness are also significantly enhanced.