基于串级控制系统控制液位的设计与分析

Design and analysis of liquid level control based on cascade control system

串级控制系统是一个双回路系统,实质上是把两个控制器串接起来,通过它们的协调工作,使一个被调量准确保持为设定值。串级系统主回路的输出用来改变副回路的设定值,起到校正的作用,副回路的任务是快速抵消落在其中的扰动,提高系统的控制品质。通过仿真分析,串级控制系统抗干扰能力比较强,曲线的波动不大,具有超调量比较小和过渡过程的时间较短等特点。稳定性得到了提高,控制效果比较好,通过对比可以看出,控制效果明显优于相对简单的单回路控制系统,从中可以体现出串级控制系统的优越性。

This paper describes cascade control system is a double-loop system, which essentially connects two controllers in series. A set value can be kept accurately by means of coordination. The output of the main loop of cascading system is used to change the set value of the secondary loop and pla y the role of correction. The task of the secondary loop is to quickly offset the disturbance falling in it, which improves the control quality of the system. The simulation results show that the cascade control system has strong anti-interference ability, little fluctuation of curve, small overshoot and short transition time etc. The stability is improved and the control effect is good. By comparison, the results show that the control effect is obviously better than the relatively simple single-loop control system, which reflects the superiority of the cascade control system.