SCR脱硝系统的串级自耦PID控制方法

Cascaded Self-coupling PID Control of SCR Denitration System

针对选择性催化还原(SCR)脱硝系统具有多扰动、大惯性和模型不确定性等特性,提出了一种基于自耦比例积分微分(SCPID)控制理论的控制方法。该方法将SCR脱硝系统中的内部扰动、外界扰动与模型不确定性等一切复杂因素定义为总扰动,进而将该系统映射为线性扰动系统,据此构建了一个在总扰动反相激励下的受控误差系统,然后针对SCR脱硝系统的内环和外环系统分别设计了自耦PID控制器,使得控制力的量纲与被控系统相匹配,最后采用3个仿真试验验证所提方法的有效性。结果表明:所提出的SCPID控制方法响应速度快、无超调、抗干扰能力强,同时具有良好的鲁棒性。

Aiming at the complex characteristics of selective catalytic reduction(SCR)denitration system with multiple disturbances,large inertia and model uncertainty,a control method based on self-coupling PID(SCPID)control theory was proposed.This method defines all complex factors such as internal disturbance,external disturbance and model uncertainty in the SCR denitration system as total disturbance,and then maps the system to a linear disturbance system.Based on this,a controlled error system under the inverse excitation of the total disturbance was constructed.Then,two separated self-coupling PID controllers were designed for the inner and outer loops of the SCR denitration system,so that the dimension of the control force matched the controlled system.Finally,three simulation experiments were conducted to verify the effectiveness of the proposed method.Results show that the proposed SCPID control method in this paper has fast response,small overshoot,strong anti-interference ability and good robustness.