基于专家PID的双模态Smith预估的漂白塔温度控制系统

Temperature control system in pulp bleaching based on expert PID and dual-model Smith predictor

漂白塔温度是多段连续漂白过程中一个重要的被控变量,具有滞后大、惯性大、干扰多等特点。基于这些问题,提出专家PID结合双模Smith预估器算法,设计了漂白塔上部温度和蒸汽流量串级控制系统。主回路采用改进的专家PID-PID双模Smith预估器,以克服滞后对系统稳定性的影响和Smith预估器对数学模型要求精确的问题。MATLAB仿真结果表明:双模态改进型Smith算法具有超调小、响应速度快等动态特性,具有较好控制效果。在实际漂白工段的应用中,可以证明该系统对漂白温度控制效果好。

The temperature of bleaching tower is an important variable in multi-stage continuous bleaching process, which has the characteristics of large time delay, large inertia and more interference. Based on these problems was put forward the expert PID with dual- mode Smith predictor algorithm and designed a cascade control system for the tower top temperature of bleaching and steam flow. The improved expert PID-PID dual-mode Smith predictor was adopted in main circuit, to overcome the time delay on the stability of the system and solve the accurate mathematical model requirement of Smith predictor. MATLAB simulation results showed that the improved dual-mode Smith predictor algorithm has good dynamic characteristics of smaller overshoot, faster response and better control effect. The practical application proved that the temperature control system for bleaching towers works well.