基于plc恒压供水变频控制系统设计.doc

基于PLC恒压供水变设计
摘要
随着社会经济的迅速发展,人们对供水质量和供水系统可靠性的要求不断提高。再加上目前能源紧缺,利用先进的自动化技术、控制技术以及通讯技术,设计高性能、高节能、能适应不同领域的恒压供水系统成为必然趋势。
本论文依据供水要求,设计了一套由PLC、变频器、远传压力表、多台水泵机组等主要设备构成的全自动变频恒压供水,具有全自动变频恒压运行、自动工频运行和现场手动控制等功能。系统有效地解决了传统供水方式中存在的问题,并具有多种辅助功能,增强了系统的可靠性。论文分析了多泵供水方式的各种供水状态及转换条件,分析了电机由变频转工频运行方式的切换过程及存在的问题,给出了实现有效状态循环转换控制的电气设计方案和PLC控制程序设计方案。
关键词:可编程序控制器,恒压供水,变频器
PLC-BASED INVERTER CONTRL CONSTANT PRESSURE WATER SUPPLY DESIGN
ABSTRACT
With the rapid social-economic development of water quality and water supply systems to improve reliability requirements. In addition, the current energy shortage, the use of advanced automation technology, control technology munication technology, the design of high performance, high energy, able to adapt to different areas of constant pressure water supply system has e an inevitable trend.
In this paper, based on water requirements, the design of a set by the PLC, frequency converter, Far pressure gauge pressure, pump unit consisting of major equipment such as automatic frequency conversion constant pressure water supply, with automatic constant frequency operation, automatic frequency run and on-site features such as manual control. System to effectively solve the traditional way of water supply problems, and have a variety of auxiliary functions, and enhance the reliability of the system. paper analyzes the various ways water pump the state water supply and conversion conditions, analysis of the motor to change jobs by the frequency of the switching frequency operation and problems of the process, given the state of the cycle to achieve an effective change of control of the electrical design and PLC control program design.
KEY WORDS: Programmable controller, Constant pressure water supply, Frequency converter
目录
前言 1
第1章恒压供水的简介 2
城市供水系统的需求 2
变频恒压供水产生的背景和意义 4
第2章恒压供水系统 6
课题研究对象 6
变频恒压供水控制方式的选择 6
系统的构成 8
工作原理 10
变频恒压供水系统中加减水泵的条件分析 11
主电路接线图 12
第3章相关器件的选型及接线 14
PLC的选型 14
PLC的接线 14
变频器