SCR烟气脱硝系统Smith预估条件积分型滑模控制  

Conditional integral sliding mode control for SCR denitrification system based on Smith predictor

作　　者：伏甲琪 郭为民[2] 刘延泉[1] 唐耀华[2] 

机构地区：[1]华北电力大学控制与计算机工程学院,河北保定071003 [2]国网河南省电力公司电力科学研究院,河南郑州450052

出　　处：《热力发电》2017年第4期93-98,共6页Thermal Power Generation

基　　金：国家重点基础研究发展计划项目(973计划)(2012CB215203)~~

摘　　要：针对具有大滞后、非线性特性的选择性催化还原(SCR)烟气脱硝系统喷氨量控制过程,提出了基于Smith预估器的条件积分型滑模控制方法。该方法将Smith预估器与条件积分型滑模控制相结合,利用Smith预估器补偿纯滞后环节,缩短调节时间;利用滑模控制的鲁棒性克服被控对象运行环境变化及外部扰动对系统的影响;利用条件积分型滑模面消除稳态误差,削弱系统抖动。并将常规PID控制、基于Smith预估器的滑模控制、基于Smith预估器的传统积分滑模控制及基于Smith预估器的条件积分型滑模控制的SCR烟气脱硝系统在100%、80%和60%机组负荷下进行了模拟仿真。结果表明:常规PID控制调节速度慢,超调大,抗扰动能力较差;3种滑模控制均对扰动有较强的鲁棒性,发生扰动之后稳定速度快,调节时间短,波动幅度很小;基于Smith预估器的条件积分滑模控制在动态过程中调节速度快,超调小,系统受到扰动后稳定速度快,变化幅度小,控制效果优于其他3种控制方式。For such characteristics as large time delay and nonlinear of ammonia spraying control in selective catalytic reduction （SCR） denitrification system, a control method based on Smith predictor and conditional integral sliding mode control was proposed. In this method, the Smith predictor was used to compensate the system delay and shorten the adjustment time, the robustness of the sliding mode control （SMC） was applied to overcome the influence of controlled object environment changes and external disturbance on the system, and the conditional integral sliding surface was used in the SMC to eliminate the steady-state error and to restrain chattering in the system. Moreover, the SCR flue gas denitrification system with general PID control, sliding mode control based on the Smith predictor, conventional integral sliding mode control based on the Smith predictor and conventional integral sliding mode control based on the Smith predictor was simulated at 100%, 80% and 60% of the actual load. The simulation results show that, for the general PID control, the regulation speed is slow, the overshoot is large and the anti-disturbance ability is poor. All the three kinds of sliding mode control have stronger robustness to the disturbance, the system has strong stability after the disturbance, the adjustment time is short and the fluctuation range is very small. For the conventional integral SMC based on the Smith predictor, the regulation speed is fast and the overshoot is small, the system has strong stability after the disturbance and the change range is small, so the control effect is better than the other three control modes.

关 键 词：滑模控制 SMITH预估器 SCR 烟气脱硝 喷氨量 鲁棒性 控制效果 

分 类 号：TM621[电气工程—电力系统及自动化] TP29[自动化与计算机技术—检测技术与自动化装置]