基于S7-1200 PLC的变频调速恒压供水系统  

System Design of Variable-Frequency Speed Governing and Constant Pressure Water Supply Based on S7-1200 PLC

作　　者：王兵[1] 徐淑华[1] 

机构地区：[1]青岛大学自动化工程学院,山东青岛266071

出　　处：《青岛大学学报（工程技术版）》2011年第2期18-22,27,共6页Journal of Qingdao University(Engineering & Technology Edition)

摘　　要：针对现代社会对恒压供水的需求,设计恒压供水系统。系统采用西门子最新面向市场的S7-1200 PLC进行逻辑控制,利用西门子变频器MM440进行压力调节。变频器和PLC作为系统控制的核心部件,时刻跟踪管网压力与给定压力的偏差变化,经变频器内部PID运算,通过S7-1200 PLC控制变频与工频切换,自动控制水泵投入的台数和电机转速,实现闭环自动调节恒压变量供水,在保持恒压下达到控制流量的目的。运行结果表明,该系统具有压力稳定、结构简单、工作可靠等特点,基本满足设计要求。According to the demand of constant pressure water supply in modern society,a constant pres-sure water supply system was introduced.It used S7-1200 PLC which is the latest products in Siemens toprocess the logic control and employed Siemens MM440 to adjust water pressure.Frequency converter and PLC are the key components of systemcontrol.They follow up the deviation between the pipe network pressure and pressure given.Through operation of PIDand switchover of frequency conversion and power frequently was controlled by S7-1200 PLC.It could automatically control the number of water pump put into operation and the speed of motor for realizing automatic regulation of close-loop and supplying water under constant pressure and variety runoff.The results indicate this system has lots of advantages of pressure constant,contracture suppleness and operation credibility,andit reaches the technical indice.

关 键 词：S7-1200 PLC 恒压供水 变频器 PID 

分 类 号：TP273[自动化与计算机技术—检测技术与自动化装置] TU991.62[自动化与计算机技术—控制科学与工程]