基于PLC的双容液位控制系统设计研究

在钢铁、石油化工、食品灌装等行业中，液位控制得到了广泛的应用。采用西门子S7—200PLC为主控制器构建双容液位控制系统，可实现对复杂对象液位的最优控制。通过上水箱和下水箱的串联，搭建一双容对象；使用稳定边界法来建立其数学模型，根据模型设定PID的初始参数，且整定最佳参数，确立PLC单回路PID控制系统，并用MCGS组态软件实现上位机对现场进行实时组态、监控。试验结果表明，系统控制稳定、可靠，能实现液位的准确控制。

Research on Control System Design of Double Containers Level based on PLC

The liquid level control is very popular in the iron and steel, petroleum chemical industry, food filling indus- try, such as to achieve the optimal complex object liquid level control, SIEMENS S7-200 PLC was used as main controller for constructing double containers level control system. Through the water and the next cistern of the series, created a pair of let object, used stability boundary method to establish the mathematical model, the model of initial parameters set PID, and set the best parameters, established a PLC single loop PID control system, and MCGS software realization of the upper machine real-time configuration and monitoring. Experimental results showed that the system is stable, reliable control and the accurate control level can be realized.