多泵恒压供水自动控制系统的研究.doc

江苏科技大学 本 科 毕 业 设 计（论文） 学 院 电子信息学院 专 业 自动化 学生姓名 翟美华 班级学号 0540303203 指导教师 庞科旺 二零零九年六月 江苏科技大学本科毕业论文 多泵恒压供水自动控制系统的研究 ——控制程序设计 The research of automatic control system for water supply of multi-stage pump and constant pressure ——The design of control program 摘 要 本文介绍了自行设计的多泵恒压供水自动控制系统，阐述了利用西门子S7-200系列CPU224 PLC和西门子公司变频器MM430来控制水泵转速的控制系统及其工作原理。 该系统采用PLC进行逻辑控制，采用变频器进行压力调节。变频器、可编程控制器作为控制系统的核心部件，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，通过可编程控制器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。 本文主要对控制程序的设计作了详细的说明，并简单介绍了供水系统的构成及其设计原理。 关键词：恒压供水；PLC；程序设计 Abstract This article introduces the multi-self-designed automatic control system for water supply of multi-stage pump and constant pressure, expounds the control system which uses Siemens S7-200 series CPU224 PLC and Siemens MM430 inverter to control the speed of pump and its working principle. The system uses PLC for logic control, and frequency converter for pressure regulating. Frequency converter and programmable controller as the core system components of the control system, tail after the change of windage between the pressure of pipelines and the given pressure at all times. Through the PID operation in internal frequency converter, the programmable controller commands the switching between frequency conversion and power-frequency, automatically control the number of input pump and motor speed, and achieve the closed-loop constant pressure and variables water supply with self-regulation, while maintaining constant pressure to achieve the purpose of controlling flow rate. This article mostly explains the design of the control procedures in detail, and introduces the formation of the water supply system and its design principles. Key words: Water supply of constant pressure; PLC; The design of Procedures 目 录 第一章 绪论 1 1.1 研究现状及发展 1 1.2 本文的主