液位串级控制系统研究与设计
在工业实际生产中，液位是过程控制系统的重要被控量，在石油﹑化工﹑环保﹑水处理﹑冶金等行业尤为重要。在工业生产过程自动化中，常常需要对某些设备和容器的液位进行测量和控制。
本设计以过程控制实验室的TKJ-2型高级过程控制实验设备为平台，设计了基于IPC-PLC的分布式控制系统。上位机采用MCGS组态软件，用STEP7软件进行编程，下位机采用西门子S7-200PLC。首先确定了中下水箱液位串级控制系统和主管流量下水箱液位串级控制系统两种控制方案。主要是看副控参数不同时其控制效果的变化，进行对比研究。然后完成了系统硬件和软件设计，硬件主要是选型和原理图的绘制，软件是完成组态画面的绘制、动画连接和PLC 程序的编写。接着对中水箱、下水箱、中下水箱、主管流量用阶跃响应曲线法进行了建模与辨识，根据响应曲线法中的PID整定公式进行了调节器参数的整定，完成了下水箱、中下水箱和主管流量单回路PID控制，最终本着先副后主的串级整定方法对中下水箱液位串级控制系统和主管流量下水箱液位串级控制系统的主调节器参数进行了整定，完成了算法对比研究。
通过系统调试得出了液位串级控制系统要比单回路控制效果好，表现在调节时间短，超调小，静差小等方面。
关键词：液位；PID整定；串级；响应曲线法
Research and Design about Level Cascade Control System
Design Description
In industrial production, the level of process control systems charged with the amount of particularly important in the petroleum, chemical, environmental protection, water treatment, metallurgy and other industries.Automation of industrial processes often need to measure and control the level of certain equipment and containers.
This design process control laboratory TKJ-2 Advanced Process Control laboratory equipment as a platform to design a distributed control system based on IPC-PLC.Host computer uses MCGS configuration software,Programming with STEP7 software,The next machine with Siemens S7-200PLC.First determine the two control schemes of the flow of the lower tank level cascade control system and competent tank level cascade control system.Mainly to see the vice control parameters while the effect of changes, a comparative study.And then complete the system hardware and software design, hardware selection and schematic drawing, the software is complete the configuration screen drawing, animations connection and PLC program to write.n on the tank, under tank, under tank competent flow step response curve method for modeling and identification,Tuning the regulator parameters according to the response curve method of PID tuning formula, completed under the tank, the next tank and competent flow single-loop PID control,Ultimately the spirit of the first vice emperor Cascade tuning method of tuning cascade control system of tank level and in charge of traffic of the main regulator of the tank level cascade control system parameters, and complete algorithm for comparative study.
Level cascade control system than the single-loop control results obtained through the system debugging, performance in the short adjustment time, small overshoot and static error, and other aspects.
Key Words:Process control；PID tuning；cascade；the response curve method
目录
1绪论 (1)
1.1研究背景 (1)
1.2国内外研究现状 (2)
1.2.1国外研究现状 (2)
1.2.2国内研究现状 (3)
1.3软件简介 (4)
1.3.1 MCGS软件 (4)
1.3.2 MATLAB软件 (5)
1.4论文主要研究内容 (6)
2系统控制方案设计 (8)
2.1串级控制系统 (8)
2.1.1串级系统的组成结构 (8)
2.1.2串级系统设计 (8)
2.2 PID控制原理 (10)
2.3 PID整定 (11)
2.3.1单回路PID整定方法 (11)
2.3.2串级系统PID整定方法 (13)
2.4方案设计 (14)
2.4.1中下水箱液位串级 (14)
2.4.2主管流量下水箱液位串级 (14)
