精品毕业论文--多泵组消防供水控制器的设计.doc

摘要
恒压供水控制系统的基本控制策略是:采用电动机调速装置与可编程控制器(PLC)构成控制系统,进行优化控制泵组的调速运行,并自动调整泵组的运行台数,完成供水压力的闭环控制,在管网流量变化时达到稳定供水压力和节约电能的目的。
系统的优点是启动平稳,启动电流可限制在额定电流以内,从而避免了启动时对电网的冲击;由于泵的平均转速降低了,从而可延长泵和阀门等使用寿命;可以消除启动和停机时的水锤效应。本文介绍一种变频调速恒压供水系统,该系统能够根据运行负荷的变化自动调节供水系统水泵的数量和转速,不仅实现了变频恒压供水,并使整个系统始终保持高效节能的最佳状态。文中详细介绍了系统的控制原理及硬件电路。
关键词: 变频器,恒压供水系统,PLC
Abstract
This paper introduces a constant pressure water supple system. It can regulate aut-omatically the quantity and rotational speed of the water pump with the variation of the load. The controlling principle and the hardware circuit are presented in detail.
The basic control strategy of the control system of constant pressure of water supply is: install the control system with motor speed adjustment and programmable logic controller (PLC), it carries out optimization control anization of the operation of speed adjustment, and adjusts the number of running pumps, completes pressure of water supply closed-loop control system, reaches the steady pressure of water supply in the changing of rate of flow in the and the purpose of economizing electrical energy. The control goal of system is the effluent pressure of pump station. The system's advantage is that starting steadily, the starting current may be restricted within specified current, so avoided the impact of work when it starts; because the average rotational speed of pump is reduced, may prolong the using of pump and valve etc.; may eliminate water hammer effect when starts and stops machines.
Key words:Inverter, Constant pressure water supply system , PLC
目录
1 绪论 1
引言 1
变频调速供水的目的和意义 1
变频调速技术的特点及应用 1
可编程序控制器的应用 2
2 变频供水器控制系统的设计 3
变频器的节能、调速原理 3
变频器控制方式的选择 3
电压空间矢量(SVPWM)控制方式 4
矢量控制(VC)方式 4
直接转矩控制(DTC)方式 4
矩阵式交—交控制方式 5
变频供水器的设计方案 5
变频供水器的工作原理 6
3 变频供水控制器的硬件设计 6
主电路设计 6
控制电路的设计 7
PLC的配置 8
EM235模拟量工作单元性能指标 10
EM235的安装使用 11
EM235工作程序编制 11
4 PLC的设计 12
PLC的编程语言 12
PLC的编程结构功能图 12