双容水箱串级控制系统分析与设计

在当今的工业生产中，串级控制一直是一个重要的课题，随着科学与技术不断地发展和进步，工业现场对串级控制的稳定性、精确度和动态过程要求愈来愈高。设计了一种依托于A3000型过程控制实验系统的串级控制方案，以S7 200 PLC为控制器，液位信号经液位变送器送至PLC，采用PID算法对数据进行处理，之后输出至电动调节阀来实现对液位的控制。采用组态王作为上位机组态软件，构建了对双容水箱液位进行实时监控的组态画面。实现对双容水箱系统进行实时、精确地监控，调节时间、稳态误差等指标均满足控制要求。

Analysis and design of double capacity water tank cascade control system

Nowadays, in the industrial production, the cascade control is an important issue. With the development of science and technology, the stability and dynamic process requirements of the industrial field to the cascade control are also higher and higher. A scheme of cascade control system based on A3000 process control experimental system was proposed, which uses PLC as the controller. Liquid level signal was sent to PLC by liquid level transmitter, using PID algorithm to process the data and then output to the electric control valve to achieve the liquid level control. Taking the Kingview as upper unit configuration software, the experiment constructed a configuration screen for real time monitoring of dual tank. The scheme can achieve high accuracy of control and real time status. The adjustment time and steady state error meet the control requirements.