基于PLC的恒压供水系统【毕业论文】.docx

基于PLC的恒压供水系统【毕业论文】.docx毕业设计
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基于PLC的恒压供水系统
摘要
PLC全称为可编程控制器(Programmable Controller)是计算机家族中的一 员，是为工业控制应用而设计制造的，具有结构灵活稳定性高的特点，在工业领 域有着很高的利用率。供水系统是国民生产生活中不可缺少的重要一环。现今， 采用最多的供水方式便是PLC与变频器控制的恒压供水系统，因为使用PLC和 变频调速技术能更有效的实现变频调速。
本论文主要设计基于PLC的恒压供水系统，系统采用三菱PLC电路系统，利 用PLC自带的PLD程序控制变频器，去改变水泵电机的供电频率，调节水泵转速。 该供水系统通过控制实际供水压力与设定压力一致，来保证在用水量变化时供水 量也随之变化，从而实现供水量与用水量的匹配。系统的实物在实验室制作完成。 实物系统能完成自动变频启动、具有缺相、欠压、过压等电气保护功能，并考虑 了三种报警状态。达到了预期的目标。
关键词：PLC；供水系统；变频调速；恒压供水
Abstract
The full name of PLC is Programmable Logic Controller. It is a member of the family computer. It is industrial control applications for the design and manufacture , with a flexible structure and high stability. It has a high utilization in the industrial field. Water supply system is important and indispensable in the national production and life. Nowadays, most of the water way is to use PLC and inverter control constant pressure water supply system. PLC and variable frequency speed control can use more effectively to achieve frequency control.
This paper is focus on the design of constant pressure water supply system based on PLC. This system uses Mitsubishi PLC circuit system, and takes the advantage of PLD in the PLC to change the water pump motor power supply frequency, adjust pump speed. This water supply system adjusts the pump speed to control the actual supply line pressure and the set pressure, then, to achieve the matching of water supply and water consumption. The physical system is made in the laboratory. It can complete the conversion starts automatically, and has the protection functions such as a phase, under voltage, over voltage, and so on. The system even considers three alarm statuses. It has achieve the desired objectives.
Key Words: PLC; water supply system; variable frequency speed control; constant pressure water supplying
1绪论 1
2变频恒压供水系统简介 3
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3恒压供水的控制方法 6
控制 6
PID控制基础 6
PID控制算法 7
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4系统设计 10
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