洛阳理工学院毕业设计（论文）
基于plc恒压供水变频控制系统设计
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洛阳理工学院毕业设计（论文） 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。
论文还提出了一些增强系统运行可靠性的措施。
关键词：可编程序控制器, 变压变频调速, 恒压供水, PLC
PLC-BASED INVERTER CONTRL CONSTANT PRESSURE
WATER SUPPLY SYSTEM DESIGN
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洛阳理工学院毕业设计（论文）
ABSTRACT
With the rapid socio-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 and communication technology, the design of high performance, high energy, able to adapt to different areas of constant pressure water supply system has become an inevitable trend.
In this paper, based on water requirements, the design of a set by the PLC, frequency converter, Far EasTone pressure, multi-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. Also made a number of papers to enhance system reliability measures.
KEY WORDS: programmable logic controller, VVVF speed control, constant pressure water supply, PLC
目 录
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洛阳理工学院毕业设计（论文）
前 言 ............................................................................................................. 1 第1章 恒压供水原理及工艺 .................................................................... 2 1.1 任务 ..................................................................................................... 2 1.2 工艺要求 ............................................................................................. 2 1.3 系统的组成和基本工作原理 ............................................................. 2 第2章 PLC概述 ...................................................................................... 3 2.1 PLC组成 .............................................................................................. 3 2.1.1 LC的输入 ......................................................................................... 3 2.1.2 PLC的输出 ................................................................................... 3 2.1.3 PLC的控制机制 ........................................................................... 3 2.1.4 PLC的定义 ................................................................................... 5 2.1.5 PLC的特点 ................................................................................... 5 2.1.6 PLC的性能指标 ........................................................................... 6 2.1.7 PLC的分类 ................................................................................... 7 2.2 PLC工作原理 .................................................................................. 7 2.2.1 循环扫描 ....................................................................................... 7 2.2.2 I/O响应时间 ................................................................................. 8 2.2.3 PLC中的存储器 ........................................................................... 9 第3章 系统硬件设计 .............................................................................. 10 3.1 恒压供水系统的基本构成 ............................................................... 11 3.2 系统控制要求 ................................................................................... 13 3.3 控制系统的I/O点及地址分配 ........................................................ 14 3.4 系统选型 ........................................................................................... 17 3.5 PLC模拟量控制单元的配置以及应用 ......................................... 17 3.5.1 EM235模拟量工作单元性能指标 ............................................. 18 3.5.2 校准及配置 ................................................................................. 18 3.5.3 EM235的安装使用 ..................................................................... 18 3.5.4 EM235工作程序编制 ................................................................. 18
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洛阳理工学院毕业设计（论文） 3.5.5 电气控制系统原理图 ................................................................. 20 第4章 系统程序设计 .............................................................................. 23 4.1 由―恒压‖要求出发的工作泵组数量控制管理 ............................... 23 4.2 泵组泵站泵组管理规范 ................................................................... 23 4.3 程序的结果以及程序功能的实现 ................................................... 23 结 论 ........................................................................................................... 33 致谢 ............................................................................................................. 34 参考文献 ..................................................................................................... 35 外文资料翻译 ............................................................................................. 36
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