变频调速恒压供水系统 变频器plc 毕业论文

摘       要
我国水厂从七十年代开始应用集中巡检，到八十年代随着工业水平的提高和计算机技术的发展，自动控制技术发展得很快。随着自动控制技术的广泛应用，大城市的水厂自动化生产程度较高，但中小城市水厂尤其是老水厂自动控制系统配置相对落后。
本论文在分析和比较了国内外供水自动控制系统的发展现状和特点的基础上，结合我国中小城市供水厂的现状，设计了一套以变频调速技术为基础的恒压供水计算机监控系统。该系统综合运用计算机技术、变频调速技术以及自动控制技术，实现了恒压供水的参数整定自动控制，保证了随时供水系统维持在最佳运行状况。
论文对计算机控制系统中的上下位机之间的串行通信进行了分析和研究，运用组件技术和多线程技术开发了串行通信控件，在自定义通信协议的基础上设计了相应的串口通信程序，实现了上位机和可编程序控制器之间的实时通讯及远程控制功能。并在此基础上研制开发了一套用于供水系统的信息管理及监控系统软件，分析了软件设计中的总体结构设计、数据库设计、数据处理软件设计等的实现。
现场调试和运行表明，该系统能够对供水过程进行自动控制，能够有效地降低能耗，提高生产管理水平。监控系统安装维护方便，运行稳定、可靠；监控软件功能齐全，人机界面友好，使用方便。
关键词：供水系统    串行通信    信息管理     PLC

 

Abstract

Centralizing scout of waterworks is started to apply in 70s in our country. In the 1980s, with the development of industry and computer technology, automation technology is progressed fast. With the widely applications of automation technology, the automatic degree of waterworks in city is much higher than the correspondence in town. Especially in some old waterworks, the equipment of automatic control system is dropped behind.
On the basis of analyzing and comparing the development and characteristic of domestic and overseas automatic system of water supply, combined with status in quo of the waterworks in our country, this paper designs a suit of computer controlling system based on variable frequency speed-regulating technology. Through using computer technology, variable frequency speed-regulating technology and automation technology, the system can make the water pressure of water supply system constantly by the way of parameters self-tuning. It assuredly makes the water supply system work on all cylinders.
Through analyzing and researching on the serial communication between host computer and PLC of computer control system, a serial communication control is developed base on control technology and multithreading technology. Serial communication program is developed base on the custom communication protocol, the function of real time communication and remote control between host computer and PLC is realized. On the basis of these programs, a information management and real time supervisory control software of water supply system is developed. At the same time, it analyzes the design of frame, database, data management and so on. The realization of these programs is also introduced.
The Operation and experiment demonstrates that the system make the work of water supply automated in some degree. It is good for energy saving and improving the management of waterworks. It’s also facility to mount and maintain, reliable to operating, and precise to supervise and control. The supervisory control software has abundant functions, kind interface and convenience to using.

 

 

Key Word：Water supply system,   PLC,   Information Management
Serial Communication

 

 

目    录
摘   要 2
Abstract 3
目   录 5
第一章 变频调速恒压供水系统的现状和发展 6
1.1变频调速恒压供水的目的和意义 6
1.2变频调速及PLC在供水行业中的应用 7
1.2.1变频调速技术的特点及应用 7
1.2.2可编程序控制器的特点及应用 9
1.3毕业设计任务及要求 11
第二章 变频调速恒压供水系统工作原理 12
2.1系统工作过程 12
2.2变频调速的节能、调速原理 14
2.3 变频调速恒压供水工况分析与能耗机理分析 17
2.3.1管路水力损失及性能曲线 17
2.3.2水泵工作点的确定和调节 18
2.3.3水泵变频调速节能分析 20
2.3.4调速范围的确定 21
2.4本章小结 22
第三章 系统监控软件的设计与实现 23
3.1系统监控软件总体结构设计 24
3.1.1数据采集和通信 25
3.1.2设备状态控制 26
3.1.3数据管理 28
3.2数据库设计 28
3.2.1数据库设计的原则 29
3.2.2数据库的建立 30
3.3监控软件结构设计 32
3.4 本章小结 33
第四章 上位机与PLC间的串行通信 33
4.1上位机与PLC间的串行通信 34
4.1.1串行通信 34
4.1.2串行通信接口标准 35
4.2通讯参数设置和通讯测试界面 38
4.2.1通讯参数设置 38
4.2.2通讯测试界面 39
4.3 PLC通信程序设计 40
4.3.1 PLC网络通信协议[19] 40
4.3.2 PLC通信程序设计 42
4.4 上位机的通信模块设计 49
4.5 本章小结 58
全 文 总 结 59
参 考 文 献 61
致       谢 63