毕业设计——PLC控制的恒压供水系统设计

青岛理工大学

毕 业 设 计（论 文）

题目 PLC控制的恒压供水系统设计

学生姓名： 林倍正

指导教师： 季鸿雁

自动化工程学院 电气工程 专业 07级4班

年 月 日 中文摘要

进去21世纪以来，随着改革开放的不断发展深入，我国城市化建设的进一步推进及其经济迅猛发展，人民的物资生活水平不断提高；与此同时，城市城镇居民需水量不断增多，对城市供水系统提出了更高更严格的要求。能否实现供水的可靠性、稳定性、经济节能性关系到城区的建设和经济的发展，也直接影响到城区居民的正常生产、工作、学习、生活。

针对目前的小区供水系统中存在的电能浪费、水资源浪费且供水质量差等一些列问题，本文研究并设计了一种变频调速恒压供水控制器。该控制器是以三菱FX2N PLC为主要器件，并与变频器、压力传感器等器件结合起来，共同构成了恒压供水系统。该系统是以管网水压为设定参数，根据本小区供水管网压力的实际需要和季节变化（如夏季为用水高峰期），可在一天中不同的时间段，设定不同的压力给定值，实现管网水压的自动调节，即实现恒压供水。

论文论述了多种方案合理性，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。最终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。

系统有效地解决了传统供水方式中存在的问题，增强了系统的可靠性。并与计算机实现了有机的结合，可通过PLC的上位计算机监控软件对压力设定值进行实时调整提升了系统的总体性能。

关键词：PLC，变频，供水，恒压

ABSTRCT

In the 21st century, with the continuous development of reform and opening up, the deep

in urbanization construction to further promote and rapid economic development, people's

material life level increases; Meanwhile, the city urban residents of urban water supply,

increasing more strict system put forward higher requirement. Realization of water supply

reliability and stability, economic energy-saving sex to urban construction and economic

development, also directly affects the normal production and urban residents work, study

and life.

Aiming at the existing in the village water supply system waste of electric, water resources

waste and poor water quality, this paper studies some problem and designed a kind of

variable frequency speed regulation constant pressure water supply controller. This

controller is FX2N PLC for the main device mitsubishi inverter, and devices such as pressure

sensor is combined to make a constant pressure water supply system. This system is for

pipe pressure, this village set parameters according to the actual needs of water supply

pipe pressure and the seasonal variation (such as summer peak), but for water in one day

and set various different time periods, realize the given value of pressure pipeline pressure,

namely, realize automatic regulation of constant pressure water supply.

This paper discusses the various solutions rationality, analyzed all kinds of water supply to

the water supply pump way status and conversion condition by frequency conversion

motor, analyzes the operating mode turn power frequency switching and existing problems.

Eventually gives realize effective electric conversion controlling state cycle design scheme

and PLC control program design.

System effectively solve the traditional way of existing problems of water supply, and

enhance the system reliability. And with computer to realize the organic union, but through

PLC PC monitor software real-time adjustment of pressure setting the overall performance

improved system.

Keywords: PLC, frequency conversion, water supply, constant pressure

目录

目录 .......................................................................................................................................................... 4

第一章 绪论 ............................................................................................................................................ 5

1.1 研究背景及意义 ............................................................................................................... 5

1．2变频恒压供水系统的国内外研究现状 .......................................................................... 5

1．3可编程控制器(PLC)的特点 ............................................................................................ 5

1.4国内外变频调速技术的发展与现状 ................................................................................ 6

1.5本课题的主要研究内容 .................................................................................................... 6

第二章 系统的控制原理及其方案论证 ................................................................................................ 7

2．1变频恒压供水系统理论分析 .......................................................................................... 7

2．1．3变频恒压供水系统的近似数学模型 ................................................................ 8

2.1.4PID算法 ................................................................................ 错误！未定义书签。

2．2变频恒压供水系统控制方案的确定 .............................................................................. 9

2．2．1供水系统的控制流程 ........................................................................................ 9

2．2．2系统运行方式的分析 ........................................................................................ 9

2．2．3系统的切换条件 .............................................................................................. 10

第三章 系统的硬件工作原理及硬件选择 .......................................................................................... 11