基于PLC的恒压供水系统设计 英文资料
基于PLC的恒压供水系统设计
58│DISCRETE MANUFACTURING│离散制造基于PLC的恒压供水系统设计Design of Constant Pressure Water Supply System Based on Plc• 齐鲁理工学院机电工程学院 张瑜 Zhang Yu 沈敏 Shen Min 刘彦芬 Liu Yanfen•山东标至信集团有限公司 李飞 Li Fei摘 要：随着科学技术的迅猛发展，传统供水方式存在的供水不稳定、能耗大等缺点日益突出。
为了提高供水质量，设计了一种基于PLC的恒压供水系统，它集先进的自动化控制技术、变频调速技术、以及通信技术于一体，采用PID闭环控制方式，大大提高了供水的稳定性和可靠性。
本系统的基本原理是用压力传感器检测管网中的水压，把测得的压力反馈至PLC内部的PID模块进行计算，得出偏差信号后调整变频器的输出频率，从而调节水泵的转速，让管网的水压稳定在设定值附近。
关键词：PLC 恒压供水 变频调速Abstract: With the rapid development of science and technology, the traditional water supply mode of water supply instability, energy consumption and other shortcomings become increasingly prominent. In order to improve the quality of water supply, this paper designs a constant pressure water supply system based on PLC, which integrates advanced automatic control technology, frequency conversion speed control technology and communication technology in one, using PID closed-loop control mode, greatly improving the water supply stability Sex and reliability.The basic principle of the system is to use the pressure sensor to detect the water pressure in the pipe network, the measured pressure feedback to the PLC inside the PID module to calculate the deviation signal to adjust the frequency of the inverter output frequency, thus adjusting the pump speed, So that the pipe network pressure stability in the vicinity of the set value.Key words: PLC Constant Pressure Water Supply Frequency Control【中图分类号】TV674 【文献标识码】B 文章编号1606-5123（2019）07-0058-031 引言通常的供水系统在用水量较高时，供水管道中的水压将下降，不能满足用户的需求；用水量较低时，供水管道中的水压将升高，超出了用户的需求，这种情况不但浪费了能源，而且还会破坏供水管道及用水设施，造成经济损失。
基于PLC的恒压供水系统设计 英文资料
Constant Pressure Water Supply System Based plcAbstract：Based one simple analysis of the methods for water supply used domestically and abroad, this paper discusses the principl e and system’s structure of automatic water supply system by using frequency conversion speed regulation in detail。
Then the system's advantages are discussed and some key problems that should be pay attention to designing are presented.Keyword: Frequency conversion speed regulation; water supply with stable pressure：PID regulator。
1、ForewordAt present，supply water in residential area and life of the skyscraper of our country generally adopt the way common frequently。
It has heavy energy consumption，high noise，and there has a great deal of questions in the source of water，such as secondary pollution etc。
And it is a kind of comparatively ideal mode to adjust the water supply device controlled rapidly with frequency conversion 。
基于PLC的恒压供水模型监控系统
基于PLC的恒压供水模型监控系统1 引言传统的供水系统采用节流阀控制水流量来满足现场的水量要求，这种方式容易造成管路压力波动过大，维护费用增高，而且十分浪费电能。
以51单片机为CPU的智能型变频调速恒压供水控制器受到了人们的广泛关注，但是，以单片机为CPU的恒压供水控制器的可靠性和抗干扰能力仍有待进一步提高。
现代自来水厂中先进仪表和设备的大量应用对其控制系统的稳定性和可靠性提出了越来越高的要求，大多数制水厂均采用集散控制系统方案来实现。
特别是随着近年来半导体技术、网络技术、软件技术等高新技术的发展，使得PLC技术和现场总线技术都得到迅速提高，向着更开放化、标准化、集成化的方向发展[2][3]。
本文采用Rockwell Automation的ControlLogix系列PLC、SLC 系列PLC、变频器及相应软件设计了一个恒压供水模型监控系统。
文中详细介绍了系统架构、设计思路及PID闭环控制，并用软件给出了最优PID整定参数。
2 系统组成及控制原理恒压供水模型监控系统组成如图1所示。
图1 系统框图所谓恒压供水，就是采用电机调速装置控制泵组调速运行，并自动调整泵组的运行台数，完成供水压力的闭环控制，在管网压力变化时达到稳定供水压力和节能的目的。
系统的控制目标是泵站总管的出水压力，系统任意设定供水压力值，与总管反馈的实际压力，进行PID调节后控制调速装置，以调节水泵机组的运行速度，从而调节系统的供水压力，即所谓的“变量恒压”概念。
恒压供水技术采用的调速装置，基本上都是变频调速器。
用变频器控制水泵向管路供水，由水压传感器反馈信号与水压设定值在变频器中构成闭环，以保水泵供水压力恒定，是目前最好的方法。
系统采用两台160SSC变频器分别控制两台电动机，以供水管的压力作为反馈信号，根据压力值进行PID调节及闭环控制(见图2)，实现恒压供水。
具体过程如下:压力传感器将水的压力信号转换为4～20mA的电流信号，SLC5/05的模拟量输入模块获得这个电流信号后，将其转换为数字量交给处理器，由处理器交给PID程序处理。
基于PLC控制的恒压供水系统设计
摘要本设计根据城市小区的供水要求，设计了一套基于PLC控制的变频调速恒压供水系统。
该系统由PLC、变频器、水泵机组、压力变送器等构成。
本系统利用变频器实现对三相水泵电机的变频调速，采用“先启先停”的原则切换运行水泵。
压力传感器检测水压信号，送入PLC并与设定值比较进行PID运算，从而控制变频器的输出电压和频率，进而改变水泵电机的转速和供水量。
这样使管网水压力始终保持在设定值附近，从而实现恒压供水。
关键词：PLC；变频调速；PID控制；恒压供水ABSTRACTAccording to the city water supply system,this paper designed a PLC-based control of frequency control water supply system.The system consists of PLC, inverter, water pump, pressure sensors and other accessories.The system uses frequency converter three-phase pump motor of the soft start and frequency control, and use "first start first stop"principle to switch to run the pump.Pressure sensors to detect pressure signals into the PLC compared with the PID set point operation and thus control the inverter output voltage and frequency, thereby changing the water pump motor speed and water supply.It makes the pipe network water pressure is always maintained around the set value in order to achieve constant pressure water supply.Keywords:PLC; frequency control; PID control; constant pressure water supply目录1 绪论 (1)1.1课题的背景及意义 (1)1.2变频恒压供水系统的国内外研究现状 (1)1.3本课题主要研究内容 (2)2 恒压供水系统总体方案设计 (2)2.1系统的主要结构及组成 (2)2.2PLC概述及其系统组成 (2)2.3变频器简介及选型 (3)2.3.1 变频器简介 (3)2.3.2变频器的基本结构 (3)3 系统硬件选择及系统电路设计 (5)3.1硬件选择 (6)3.1.1 PLC及其扩展模块的选型 (6)3.1.2 变频器的选型 (6)3.1.3 水泵机组的选型 (7)3.1.4 压力变送器的选型 (7)3.1.5 液位变送器选型 (8)3.2系统主电路分析及其设计 (8)3.3系统控制电路分析及其设计 (9)3.4PLC的I/O端口分配及外围接线图 (11)4 系统的软件设计 (14)4.1 系统软件设计分析 (14)4.2PLC程序设计 (15)4.2.1 控制系统主程序设计 (15)4.2.2 控制系统子程序设计 (19)4.3PID控制器参数整定 (22)4.3.1 PID控制及其控制算法 (22)4.3.2 系统的近似数学模型及参数取值 (23)5总结 (24)参考文献 (25)附录 (26)致谢 (34)1 绪论1.1 课题的背景及意义城市中各类小区的供水系统是小区众多基础设施当中的一个重要组成部分。
英文文献-恒压供水
Constant pressure water-supplyWith the progress development of social economic and the construct scale of city continuously enlarge, increasing of population and standard of living of people continuously improved, more and more demanding to quantity, quality and stability of water supply bring forward in city. The automatic degree of waterworks in town is much lower than the correspondence in city. Especially in some old waterworks, the equipment of automatic control system is dropped behind. The control of unit ismainly depended on manual operating of watches. The process of control is very complicated and that manual control can't meet the change of pressure in the pipes and the water level of the pure pond. It also can't act the proper feedback in time. For the sake of water supply, the electromotor unit usually works in the state of over charge. Not only efficiency of electromotor is low and electricity consuming is bigger, but also the pressure of pipes is overload in long term. On the basis of analyzing status in quo of the waterworks in our country, this paper designs a suit of constant pressure water supply automatic control system by using variable frequency speed-regulating technology based on PLC.The system is made up of PLC, transducer, units of pumps and electromotors, pressure sensor, industrial control computer and console. The system is used a transducer to make four electromotors starting, running and timing. The two high-power electromotors(220Kw) and low-power electromotors(160Kw) is partly circulated. To connect control computer with PLC and realize supervisal, a real time supervisal control software of water supply system is developed. The software has the function of data connection, communication, state control of facilities and data management.To tune up the frequency of power supply by the transducer in the system, this adjusting make the speed of electromotor and performance curve of pump change. At last, it make the status of a pump alter. Through analyzing the figure of energy wasting of pump, the quality in pipes is direct proportion of the speed of pump if the speed of pump is reduced. The power of electromotor fell the cube of the speed of pump. So the energy wasting of constant pressure water supply based on variable frequency speed regulating technology is envident less than the traditional mode isused throttle to supply water.Through using STEP7 MicroWin program software of SIMENS Company in German in the control system, a PID controller of pressure control within PLC isdesigned. The controller can compare the measure value and the value in advance of pressure. Through‘real-time controlling the output voltage and frequency of transducer, the output quality of pump is changed along with the changing of pump's speed. It makes the pressure of pipe self-regulating and steady in the scheduled value.There are some drawbacks such as conversion current is great, easy to burn the fuse and switch if off in variable frequency to working frequency of high-power electromotor. In the former researching, the conversion of variable frequency to working frequency is only emphasized the speediness. The conversion is usually failed because the key is not the speediness of conversion. Through analyzing and researching the problem of variable frequency to working frequency of high-power electromotor in theory, the key of conversion is pointed out in the paper. On the basis of analyzing equivalent circuit diagram and vector-diagram of induction-motor, the phase of working frequency power whether or not consistent with the output phase of variable frequency power at the moment of conversion is the key to decide whether the conversion is successfully.With the application of phase detector in industrial experiment on the spot, when the phase of working frequency power supply is consistent with the output phase of variable frequency power supply, PLC sends out the instruction to switch off the output of transducer. The electromotor is connected with the industrial frequency voltage after it was disconnected from the output of transducer. The conversion time is less than half hundred ms. The switch off current of variable frequency to working frequency is around one and half times of rating current of electromotor when the measures is made. It is succeed to solve the problem of variable frequency to working frequency and realizing the smooth conversion of high-power electromotor. It reduced the impact on power supply and equipments, too.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.恒压供水随着社会经济的飞速发展，城市建设规模的不断扩大，人口的增多以及人们生活水平的不断提高，对城市供水的数量、质量、稳定性提出了越来越高的要求。
基于PLC和HMI的变频恒压供水系统设计
０ 引言
随 着社 会 的发展 与进 步 ，城市 高层 建筑 供水 问 题 日益 突 出 ，一 方面 要求 提高 供水 质量 ，不 能 因压 力 的波 动造 成供 水 障碍 ，另一 方面 要 求保证 供水 的
王 晓瑜 。 ’
Ｗ ＡＮＧ ａ — ｕ ， Ｘｉｏ ｙ １ ２
（． １ 西安建筑科技大学 机 电工程学院 ，西 安 ７ ０ ５ ；２ 西安外事学 院 工学 院，西安 ７ ０ ７ ） １０ ５ ． １ ０ ７
摘
要 ： 介 绍用三菱Ｆ ２ Ｌ 、变频器和人机界面 ， Ｘ ＮＰ Ｃ 设计恒 压供 水控 制系统。分析系统的控制原理 ， 设计系统流程图及软件程序。实践结果证明 ，系统运行稳定，可靠性好，实现住宅恒压供水
水 泵 在 高 速 下 运 行 ；当 用 水 量 极 大 或 发 生 火 灾 及 其 他 需 要 大量 用水 时 ，由 Ｐ Ｃ控 制 两 台水 泵 同 时 Ｌ 启 动 ，以 保 证 压 力 的稳 定 。 为 了 延 长 水 泵 的 使 用
组 、储 水 罐 、 储 能 罐 等 组 成 。恒 压 供 水 控 制 系 统
统 主 电 路 单 元 、控 制 回路 单 元 及 人 机 界 面 单 元 等 若 有 需求 ，可 向 笔者 索取 ） 。 从 图 ３中可 知 ，通 过 来 自远 端 压 力 表 的 反 馈 值 与设 定 值 的 比较 ，经 变 频 器 ＰＤ 控 制 时 的 输 出 Ｉ 频 率限 制 设 定 的百 分 比 ，一 次 延 时 使 系统 的 震 荡
和 节能的环保要求 。
关键词 ： 恒压供水 ；Ｐ Ｃ Ｌ ；变频器 ；Ｈ ＭＩ 中图分类号 ：Ｔ ７ ３ Ｎ ７ 文献标识码 ：Ａ
机电一体化毕业设计：PLC控制的变频-工频双回路恒压供水控制系统的设计
GDGM-QR-03-074-B/1Guangdong College of Industry & Commerce毕业综合实践报告Graduation synthesis practice report题目：PLC控制的变频－工频双回路恒压供水控制系统的设计(in English) Design of frequency - frequency PLC control double loop constant pressure water supply control system系别：电气自动化系班级：12机电一体化（3）班完成日期：6/2015摘要本设计根据供水要求，设计了PLC控制的变频－工频双回路恒压供水控制系统。
变频恒压供水控制系统由可编程控制器、变频器、水泵机组、压力传感器、工控机等构成。
本系统包含两台水泵电机，它们组成变频循环运行方式。
采用变频器实现对四相水泵电机的软启动和变频调速。
压力传感器检测当前水压信号，送入PLC与设定值比较后进行PID运算，从而控制变频器的输出电压和频率，进而改变水泵电机的转速来改变供水量，最终保持管网压力稳定在设定值附近。
通过工控机与PLC 的连接，采用组态软件完成系统监控，实现了运行状态动态显示及数据、报警的查询。
变频恒压供水技术具有较先进的技术、水压恒定、操作方便、运行可靠、节约电能、自动化程度高等有点。
关键词：变频恒压供水系统；可编程控制器（PLC）目录一、绪论 (1)（一）课题的提出 (1)（二）变频恒压供水系统的国内外研究现状 (1)（三）本课题的主要研究内容 (2)二、控制方案确定及系统的理论分析 (3)（一）变频恒压供水系统控制方案的确定 (3)1.控制方案的比较和确定 (3)2.变频恒压供水概况 (4)（二）变频恒压供水系统的理论分析 (4)1.变频恒压供水系统的节能原理 (4)2.电动机的调速原理 (5)（三）变频恒压供水系统的设计构想 (6)1.变频恒压供水系统的组成和原理图 (6)2.变频恒压供水系统控制流程 (8)3.水泵切换条件 (9)三、系统的硬件设计 (10)（一）主设备选型 (10)1.主设备选型 (10)2.PLC 及其扩展模块的选型 (11)3.变频器的选型 (11)4.水泵机组的选型 (12)5.压力变送器的选型 (12)6.液位变送器的选型 (13)（二）系统主电路分析及其设计 (13)（三）系统控制电路分析及其设计 (14)（四）PLC的I/O端口分配及外围接线图 (16)四、系统的软件设计 (18)（一）系统软件设计分析 (18)（二）PLC程序设计 (19)1.控制系统主程序程序设计 (19)2.控制系统子程序设计 (21)（三）PID控制器参数整定 (30)1.PID 控制及其控制算法 (30)2.PID 参数整定 (31)五、结束语 (33)参考文献 (34)致谢 (35)附录 (36)附录图1主电路图 (36)附录图2控制电路图 (37)附录图3主程序流程图 (38)附录图4主程序梯形图 (39)一、绪论水是生产生活中不可缺少的重要组成部分，在节水节能已成为时代特征的现实条件下，我们这个水资源和电能短缺的国家，长期以来在市政供水、高层建筑供水、工业生产循环供水等方面技术一直比较落后，自动化程度低。
恒压供水控制系统
PLC控制的变频调速恒压供水摘要随着社会的发展，恒压供水越来越重要。
本系统以PLC与变频器控制水泵工作，根据压力给定的理想值信号及管网水压的反馈信号进行比较，变频器根据比较结果调节水泵的转速，达到控制管网水压的目的。
文中重点叙述了变频节能原理，恒压供水原理及PID控制方式。
并提供控制系统硬件和控制软件，经现场模拟调试成功，实现运行可靠、节能、低噪，维护简单等效果。
关键词：恒压供水；PLC控制；闭环PIDAbstractWith the developme nt of society, more and more importa nt in the con sta nt pressure water supply. This system uses PLC and inverter control pumpworking pressure, according to the given ideal value sig nal and pressure of the pipe n etwork compares the feedback signal, frequency converter according to thecompared result, adjust the pumpspeed, to control the pressure of the pipe n etwork for the purpose of. This paper mainly describes the en ergy sav ing prin ciple of variable freque ncy, con sta nt pressure water supply theory and PID con trol. And provides the control system hardware and control software, the simulati on debuggi ng success, to achieve reliable operati on, en ergy sav in g, low no ise, simple maintenance and effect. Key Words： Constant pressure water supply ; PLCcontrol ; Closed loop PID1引言随着我国社会经济的发展，城市人口和城镇建设规模不断扩大，高层建筑与日俱增。
恒压供水外文翻译
外文文献原稿和译文原稿The water supply system is the national production and life indispensable important one annulus. The traditional method of water supply area, water pollution, infrastructure investment, but the main drawback is that water can not be kept constant, causing part of the equipment can not work normally. Variable frequency speed control technology is a new mature AC motor stepless speed regulating technology, its unique excellent control performance is widely applied to the speed control field, especially in water supply industry. Due to the safety in production and the water quality of special needs, for constant pressure water supply with the stringent requirements, so the frequency control technology has been more in-depth application. Constant pressure water supply ways to advanced technology, constant pressure, convenient operation, reliable operation, energy saving, high degree of automation, in pump station water supply can perform the following functions:( 1) to maintain constant pressure;( 2) the control system can be manual or automatic operation;( 3) a plurality of pump automatic switch operation;(4) system of sleep and wake, when people stop when water, the system is in a sleep state, until the water demand automatically wake;(5) adjusts the PID parameters on line;( 6) pump unit and circuit protection detection alarm, signal display.The actual pressure of the pipe network feedback and a given pressure were compared, when the pressure of a pipe network is low, increase the output of frequency converter, pump speed faster, water supply quantity increases, forcing the pipe network pressure rise. Vice pump speed slow down, reduce the water supply pipe network pressure drop,, to keep the constant pressure water supply.System hardware structureSystem uses a pressure sensor, PLC and inverter as a central control device, to achieve a desired function. Source: network transmission and distribution equipmentinstallation in pipe line pressure sensor, for detecting the water pressure of the pipe network, converting pressure is 4 ~ 20 mA current or voltage signal is 0 ~ 10V, supplied to the inverter.Converter pump motor control device, in accordance with the constant water pressure needs to be 0 ~ 50 Hz frequency signal supply pump motor, adjust its speed SAJ converter is powerful, i.e. pre-programmed set parameter set, will use the required in the process of setting the number of parameters is reduced to a minimum, default value according to the application parameter of the macro choice and different. The system adopts the PID control application macro, closed loop control. Inverter based on a constant pressure corresponding to the voltage setting value and from the pressure sensor to obtain the feedback current signal, the use of PID control macro automatically adjust, change the frequency output value to adjust the control the speed of the pump motor, to ensure that the pipe network pressure constant requirements. PLC IntroductionPLC-Programmable Logic Controllers are widely used in recent years the field of industrial control Such as metallurgy, steel, production lines, etc Its main feature is its stable performance, high control precision and easy maintenance. With PC connection, compiled in the production process according to the corresponding program will convert digital signals into analog signal input commands output instructions to control the implementation of components to achieve automatic control purposes. Currently, the main aspects of the music program-controlled fountain imported lighting console and its matching control decoder, once the failure is not easy to repair, the price is more expensive. Using PLC technology, you can use an ordinary PC to replace imported lighting control, easy maintenance, low cost PLC article on how to use music technology to analyze the problem of program-controlled fountain.The application of inverter in the constant pressure water supply Ⅰ．The characteristic and analysis of variable frequency speed regulation The water users in general is dynamic, so the water supply is insufficient or excess water supply situation has occurred. The water supply and the imbalance between the concentrated reflection in water supply pressure, namely water and watersupply is less, the low pressure; less water consumption and water supply, the pressure. Keep the water pressure constant, can make the water supply and water balance between water supply and water for a long time, that is, less water when the water is less, so as to improve the quality of water supply.Constant pressure water supply system for the user is very important. In production and living water, if water supply due to insufficient pressure or short of water, may affect the quality of life, serious when can influence the survival safety, such as when a fire occurs, if the water pressure is insufficient or water supply, can quickly fire, may cause significant economic losses and casualties. Therefore, water area by means of Arts is the constant pressure water supply system, can produce great economic benefit and social benefit.With the development of electric power technology, frequency conversion technology perfected, with variable frequency speed control as the core of the intelligent water control system replaced the previous high level water tank and a pressure tank and water supply equipment, stable starting, the starting current can be limited within specified current, thereby avoiding the starting time of the impact of power grid; because the average rotational speed of pump is reduced, which can extend the pumps and valves and other things of life; to eliminate the start and stop of the water hammer effect. The stable and safe performance, simple and convenient operation, and complete and thoughtful function, will make the water supply and water conservation, energy saving, labor saving, ultimately achieve efficient operation.Ⅱ．The application of variable frequency control constant pressure water supply modeUsually in the same way in the water supply system, setting multiple common pump, water supply when the quantity of multi pump full open, water supply on one or two hours. In the variable frequency speed control for constant pressure water supply, in two ways, one is all pumps with a frequency converter; and each water pump with a frequency converter. After a method based on pressure feedback signal, operated by PID automatically adjusts the output frequency of the inverter, change the speed of the motor, eventually reaching the purpose of network voltage, a closed loop,is relatively simple, but the cost is high. The previous method of low cost, less than kind of poor performance, but the control program is complex, is the future direction of development, such as the Shanghai arts and science and technology of constant pressure water supply control system can realize a inverter control any number of motor function. The principle mentioned below are multiple motor inverter drive system.Ⅲ．The PID control principleAccording to the feedback principle: to maintain a physical quantity unchanged or essentially unchanged, it should bring the physical quantity and the constant comparison, to form a closed loop system. We want to keep the pressure constant, so we must introduce the hydraulic feedback value with a given value, thereby forming a closed loop system. But the control system is characterized by nonlinear, inertial system, now the control method combined with PID in the large pressure fluctuation, using fuzzy control, in order to accelerate the response speed in the pressure range; using PID to maintain static accuracy. This through the PLC and intelligent instrument can show the algorithm, while the PLC programming to show when the pump frequency and inverter switching between. Practice has proved that, using this method is feasible, and the cost is not high.To maintain the constant pressure water supply network, according to the feedback theorem in network management system installed on the pressure transmitter as a feedback element, because of long, large diameter pipe system of water supply, pipeline pressure charging are slower, so the system is a big time lag system, is not easy to directly with PID regulator for control, and adopts PLC is involved in the control of the way to achieve the control system regulates the effect. Ⅳ．Frequency controlUsing frequency control to realize constant pressure water supply, with adjustable valve to realize constant pressure water supply, energy-saving effect is very significant ( according to the specific circumstances calculated ). The utility model has the advantages of:1, starting balance, the starting current can be limited within specified current, thereby avoiding the starting time of the impact of power grid;2, because the average rotational speed of pump is reduced, thereby prolonging the service life of pump and valve etc.;3, can eliminate the start and stop of the water hammer effect;Generally speaking, when performed by a frequency converter to control a motor, just make the inverter motor capacity and the actual capacity of the motor can be. When one inverter control two motors, principle of inverter motor capacity should be equal to the capacity of the two motors. But if the peak load of water more than two pumps at full supply a lot of difference, Shanghai arts and science and technology engineers suggested, may be considered appropriate to reduce the capacity of the frequency converter, but attention should be paid to leave enough capacity.Although the pump at low speed, small working current of the motor. However, when the user with the water volume changes frequently, the motor will be in frequent ascending, descending and ascending, descending speed state, the current speed slightly over the motor rated current, cause the motor overheat. Therefore, the motor thermal protection is required. For this due to frequent ascending, descending speed and accumulated temperature rise, frequency converter in electronic thermal protection function is difficult to play a protective role, so should be used in thermal relay for motor thermal protection.The main function of preset, the highest frequency should be rated motor frequency converter the highest working frequency. Ascending, descending speed time in using PID regulator case, ascending, descending velocity time should be set to be short, so as not to affect the PID adjuster determines the dynamic response process. Such as the frequency converter with PID regulation function, as long as the preset set PID function effectively, the setting of the acceleration and deceleration time will automatically lapse.Ⅴ．Constant pressure water supply system1, power: the optimal energy-saving control software, so the pump to achieve maximum energy efficiency;2. according to the actual water use, water saving setting pressure of the pipe network, the automatic control pump out the water, reducing the water running, leakage phenomenon;3, reliable operation: by the frequency converter to realize the soft starting of pump, the pump is realized by frequency to the frequency of the bumpless transfer, prevent network impact, to avoid the pipe network pressure gauge, pipe rupture.4, network function : the whole Chinese industrial control configuration software, real-time monitoring of each site, such as the motor voltage, current, frequency, pipe network pressure and flow. And the ability to accumulate each site electricity use, cumulative per pump out the water, at the same time to provide various forms of print statements, in order to analyze the statistical.5, flexible control: section water supply, water supply, manually select working mode.6, self protection functions: such as a pump failure, take the initiative to the PC alarm information, at the same time start standby pump, in order to maintain water balance. If the control system failure, the user can directly operate manual system, in order to protect the water supply.Ⅵ．The system application1, water plant, pressure pump2, the residents living area, hotels and other buildings3, enterprise production water4, boiler circulating water system5, the farmland irrigation systemCompared with other water supply, frequency constant pressure water supply system, in addition to having significant energy-saving effect obviously, has the following advantages:1, constant pressure water supply technology by using the frequency converter to change the motor power supply frequency, and to adjust the pump speed to change the pump outlet pressure, than by regulating valve control pump outlet pressure, has a reduced resistance greatly reduced the effectiveness of the interception loss.2, because of the variable pump work in the frequency condition, at its outlet flow rate is less than the rated flow rate, pump speed is reduced, reducing the abrasion of the bearing and fever, to extend the pump and motor of the service life of the machine.3, pump adopts soft starting mode, by setting the accelerated acceleration time, avoid the motor starting current impact, on the grid voltage fluctuations caused by the impact, but also to avoid the sudden acceleration caused by motor pump systems surge. The complete elimination of water hammer.4, to realize automatic control, operating personnel do not need frequent operation, reduces labor intensity of workers, saves the manpower.Working principleTransducer in the water system in conjunction with the introduction of small Plc technology not only change the traditional use of water control valves, and in energy conservation, Hengya control, are very good results, the paper introduced a transducer --PLC control technology in the pump control applications.Control system using one Taiwan transducer can bring three pumps, pumps can work at the frequency pump in the conventional model can work in the frequency conversion pump model. At the pump only in frequency conversion or one of the working frequency mode through two relays efficient ensure its security and reliability. System structure as figure 1 shows, the use of placement in the life of water pressure Biansongqi water pressure signal transmission to the regulator, in accordance with the regulator to set the value and warning of lower compared to send signals to the Plc and the transducer, the system has stopped pumping from regulator pressure level signals and transducer frequency range signal, if the low pressure, regulator to the Plc a pressure lower signal Plc activation transducer, and a frequency conversion 1st pumps work state, and the output frequency gradually increasing, after a period of adjustment, such as pressure is low, then, Plc for 1st pumps in the frequency of work, 2nd pump frequency conversion work at the state pumps, such as pressure is low, 2 pumps at the frequency for the state and make the state 3rd pumps in frequency conversion work, and so on. When the pressure regulator to limit the police on duty, regulator output reduction, transducer frequency reduced to the low frequency range set value at a given frequency transducer signals to the lower PLC,PLC According to Kai principle pause control pump operation sequence, for example, Plc received lower frequency signals, the system pumps state is the frequency 1st, 2nd-frequency, 3rd frequency conversion, the first time 1st pumpsactivated, the first stop, then as the pressure was high, then stopped on the 2nd pumps. Each system is used for slow start, high-speed operation in order to enhance operational efficiency.Constant pressure water supply equipment1, frequency conversion control cabinet structure and principleVariable frequency pump control system through the pipeline pressure, the inverter system with built-in PID regulator operation, regulate the output frequency, and then to achieve a constant pressure water supply pipe network. The frequency of the transducer overrun signal ( generally used as pipeline pressure limit signal ) can be timely informed the PLC variable frequency pump switch. In order to prevent the occurrence of water hammer, pump switch is linked to the outlet valve.Variable frequency water pump control cabinet works as follows:Various types of directly from the municipal pipe network water tank ( box ). Such as: the construction of various types of ground water reservoir water, ground boiler cold water supplying, ground air conditioning system cooling water circulating pool water, ground water circulating pool water, fire and spray for ground water reservoir inlet. The intelligent variable frequency constant pressure water supply energy-saving control cabinet, frequency conversion water supply energy-saving control cabinet assumes the entire system is composed of four pumps, a converter, a PLC and a PID and a pressure transmitter and a plurality of auxiliary components. The function of each part are as follows : installed in the water supply pipe network pressure pressure transmitter will be converted into 1-5 volt electrical signal; frequency conversion speed regulator used for adjusting the pump speed to regulate the flow; PLC for logic switching. In addition, the system is also equipped with an auxiliary circuit, in order to ensure automatic control system failure can be regulated through the artificial way to maintain the system operation, to ensure continuous production.2, frequency conversion control cabinet features:According to tank ( box ) the height of the water level in the automatic control electromagnetic valve ( or electric valve ) opening and closing, in order to control thewater tank ( pool ) of the water inlet and the tank ( box ) to automatically maintain a certain amount of water for use by the user.3, frequency conversion control cabinet selection instructions of variable frequency water pump control cabinet is mainly composed of variable frequency control box, a pressure sensor, pump etc.. Frequency conversion control cabinet comprises a circuit breaker, inverter, contactor, an intermediate relay, PLC etc..Variable frequency water pump control cabinet system selecting principlePump head should be greater than the actual height.Pump flow sum should be greater than the actual maximum supply quantity.Selection of variable frequency pump control cabinet:According to the user's water supply and water height determination model of pump and the number, then the control cabinet selection.May foresee: The future frequency conversion technology will be able to develop to the below direction:(1)high performanceThus including internal leveling circuit, the contravariant electric circuit all use the high frequency PWM electric circuit to cause the input, the output all are sine waves; Uses the multi-densification regarding the large capacity frequency changer and many machine is parallel; Reduces frequency changer own loss, the realization high efficiency; Realizes autotune or from the optimization, the remote control and controls far; Even more faces the user, further enhances the workability and Maintainability: Turns towards, the featherweight development small, as well as reduces the cost and so on.(2)IntellectualizationIncluding two aspects: Reduces the hardware as far as possible, realizes the hardware software; Uses the intelligent electric power electronic device and other intellectualized part. The integration is the intellectualized foundation.(3) entire digitizationIn recent years, each kind of modern control theory, the expert system, the fuzzy control and the neuron control and so on all were the development hot spots, will cause the electric power electronic control technological development to a brand-newstage. Estimated the 21st century entire numerical control the application will be more widespread thoroughly, even will substitute for the simulation control.(4) SystematizationFrequency conversion technology development is inseparable from the development of related technologies, frequency conversion technology development in the 21st century is to grid, regulators, rely machine, electric motors, production machinery and control systems as a whole, from the system for consideration. ConclusionA high quality variable frequency control box, from the design, technology, manufacturing, transportation, packaging, is the actual products require a higher request, all aspects of quality assurance, can make the high quality and the level of control cabinet.Constant pressure water supply used in the field of1, water supply, community living and fire water supply system, and can also be used for hot water supply, constant pressure sprinkler system.2, industrial business life, production water supply system and the other factory needs constant voltage control areas ( such as air compressor system of constant pressure gas supply, constant pressure air supply ). On various occasions, the constant pressure control, cooling water and circulating water supply system.3, sewage pumping stations, sewage treatment and sewage lifting system.4, agricultural irrigation, garden sprinkler, waterscape and music fountain system.5, hotels, large public building water and fire system.译文供水系统是国民生产生活中不可缺少的重要一环。
plc供水外文文献
Transducer and PLC in the water control system applicationsM. Bani Younis and G. FreyJuniorprofessorship Agentenbased AutomationUniversity of KaiserslautemP. 0. Box 3049, D-67653 Kaiserslautem, Germany1.IntroductionCurrently, the water level control in a large part of the electrical pumps are not towing gear shift system, no gear shift most of the electrical energy consumed in the water supply to the frequent changes in the pumps stopped. This not only makes the electrical work in inefficient zones, cut short the useful life of electrical and electrical equipment for the frequent failure to stop the high rate, leading to serious waste of water resources, system maintenance, repairs larger workload.With high living water and industrial water gradually increased, the traditional control methods that are outdated. Originally used for artificial water level control, water level due to the lack of accurate positioning hour monitoring, it is difficult to accurately controlthe pumps have stopped; Using buoys or mechanical control devices such as water supply situation has made some changes, but because of mechanical failure more devices, poor reliability to maintenance will face great trouble.Frequency conversion technology, with its superiority in the area of energy efficiency and Hengya pressure control system can be solved by the existence of the above problems. Consider selecting Chanpianji or Plc and transducer combination at the core of the system can achieve a better control results. But in software design, Plc programming of more than Shanpianji concise, and visual; From the hardware interface considerations, Shanpianji circuit slightly complex; From the economic considerations, the Plc processes are mature, cost and small Plc Shanpianji a little, because the system parameters to be adjusted in accordance with the situation on the ground, Plc software, the time parameters adjustments simpler, so more conducive to after-sale personnel.Programmable Logic Controllers (PLCs) are a special type of computers that are used in industrial and safety critical applications. The purpose of a PLC is to control a particular process, or a collection of processes, by producing electrical control signals in response to electrical process- related inputs signals. The systems controlled by PLCs vary tremendously, with applications in manufacturing, chemical process control, machining, transportation, power distribution, and many other fields. Automation applications can range in complexity from a simple panel to operate the lights and motorized window shades in a conference room to completely automated manufacturing lines.With the widening of their application horizon，PLC programs are being subject to increased complexity and high quality demands especially for safety-critical applications. The growing complexity of the applications within the compliance of limited development time as well as the reusability of existing software or PLCmodules requires a formal approach to be developed [I]. Ensuring the high quality demands requires verification and validation procedures as well as analysis and simulation of existing systems to be carried out [2]. One of the important fields for the formalization of PLC programs that have been growing up in recent time is Reverse-engineering [3]. Reverse Engineering is a process of evaluating something to understand how it works in order to duplicate or enhance it. While the reuse of PLC codes is being established as a tool for combating the complexity of PLC programs, Reverse Engineering is supposed to receive increased importance in the coming years especially if exiting hardware has to be replaced by new hardware with different programming environmentsTransducer in the water system in conjunction with the introduction of small Plc technology not only change the traditional use of water control valves, and in energy conservation, Hengya control, are very good results, the paperintroduced a transducer --PLC control technology in the pump control applications.2. System control theory and composition1.constant pressure water system basic working principleSystem uses Automatic Frequency Control regulation or pump motor speed. Plus or minus pump.It is primarily by the Frequency Control System.PID regulator,pressure sensors,liquid level sensor power control circuits and other conponents.Host users control system or control board light over-the-countertransactions,buttons,switchto understand and control systen operation,Based on the PID control mode,the operator interface settings in water pressure,PLC to pressure settings and measured valucs for the deviation PID operation and regulation of distribution through inverter pump speed,so that water pressure was maintained at the set value.2.Systen hanlware configurationThe system uses Siernens S7-200 PLC and itsconfiguration software constitute a constant WinCC V6.0 Water pressure control system,water pressure monitoring process.Industroal Ethernct controller for PLC and the operator station computer communication betwween the Remote I/O network for the PLC and the operator station compuler communication betwween the Remote I/O network for the PLC controller and inverter,the soft starter of communication betwween equipment.PLC controller mainly used to monitor and control water and electricitysystems.For1#-4#pressurized pump converter using the ABB Acs510-01-031A4 inverter,HMI operatostation selection DELLconputers,conputer,Industrial Ethernet server card Siemens conmmunications company CP1612.3.Software design of SystenThe control system software company Siemens PCS7V5.2 package.STEPV5.2 PLCcontroller.HMImonitoring system used WinCCV6.0 version.HMI server and operating station are using the Windows2000 operating system to have anopen programming environment.Heating Sation Wincc configuration control software maior constant pressure water system and coal Gallery in two parts.Implemention of the system of automatic detection and automaticcontrol.Detection constant pressure water and coal Gallcry equipment operation parameters.the real-time data acquisition.uploads.real-time data acquisition.uploads,real-time display and recording.Ciontrol unit operation.fault alarm and automatic parking operation .Theconstant pressureof water supply pressure system configuration parameters.real-time monitoring regulatory pressure pumps water pressure and so valued.CoalHanding Gallery in to control the volume.of coal to speed,to monitor the quality of coal (coal crushing degree of quality and impurity)4. PLC-Based Fuzzy Constant water supply system design constant pressure water system components1 Constant Pressure Water FormFrom the water supply system programmable controller,inverter,pressure transmiter,and the constact group on the pump unit and other components.Programmable controller selection of AB ControlLogix system.It includes Logix5550 controller,analog input modules,digital input and output modules and communication modutes.Which analog input modute used to test the water pressure on the export signal,digital input module and valves Kaistopped.Inverselection of AB 1336 Plus Inverter.Inverter and Devi2 cenet controller thtough the network for communication.2.Constant Pressure Water PrincipleThe outlet channel of pressure sensor installation will export water pressure signals are converted to electrical signals, send PLC fuzzy inference operation, the output control signals to the converter, regulating the operation of pump motor speed, until the actual elimination of hydraulic pressure and set the deviation, constant voltage supply. Programmablecontroller can control pumps Kai stopped. When the system started working, inverter control from start on 1st pump frequency operation. If users increased consumption of the converter output frequency up to 50 Hz, the pressure will still be less than the set value, then after some time delay, on the 1st of the pump switching frequency operation; Inverter start again on the 2nd pump operation. If pressure is less than the set value, they will be on the 2nd to pump switching frequency operation; Inverter start again on the 3rd pump operation until the output pressure settings to achieve so far. However, if users to reduce water consumption, in accordance with the “Kai-stop” principle will be followed with pumps. This cycle repeatedly to achieve constant pressure water system.3.Fuzzy2PI control algorithmAs the water supply system in many areas (such as the pipe network and pumps) nonlinear, time-varying, and the variables still exist between the cross-coupling, so it is difficult toestablish a precise mathematical system model. For such a complicated process that merely using the conventional PID control is difficult to achieve the desired control. Fuzzy control is not dependent on the mathematical model and the right parameters sensitive to the merits, Fuzzy used to control the water supply system, we can improve the control system dynamic performance. But Fuzzy Control System steady-state performance is poor, this design of a dual-mode Fuzzy2PI control, As shown in figure 2, and its design thinking is; when the pressure is greater error when using fuzzy control, to obtain good transient; When the pressure on the stead-state error into smaller, switched to process from PI control, to obtain good steady precision. PI control algorithms and fuzzy control algorithms are PLC, switching time by a computer program based on prior to the error autormatically.The system uses two-input single-output fuzzy controller. to pressure the desired value and the measurement of e error and the error as a fuzzycontroller input linguistic variables, transducer frequency variation u language as output variables. To e error, the error rate ec and control volume u fuzzy subset of( NB,NS,ZE,PS,PB) and they quantified the domain of seven grades, (-3,-2,-1,0,1,2,3). Fuzzy subset of the membership function used triangle. Initial experience of fuzzy control rules, as shown in table 1. Under these rules calculation of the total fuzzy relation R:Where x, U fuzzy relationship matrix on behalf of the “Cartesian” and the “and” operator. According minimax inference rules synthesis of output variables language domain of fuzzy sets U: U Finally, the weighted average method used for solutions vague and fuzzy volume U converted into precise amount u. The process is carried out offline, eventually Fuzzy Control Table, as shown in table 2. This form of the PLC memory storage, real-time control, fuzzy control would streamline the process for finding inquiries on the questionnaire process.4.Parametric Selection of Frequency-water systemA reasonable selection pressure control parameters constant pressure to achieveenergy-supply system. The realization of is this objective the key is pressure control parameter selection, usually pipe network pressure control point two choice: a pipe network is the most negative pressure on constant pressure control and the other is the constant pressure pump outlet.Pressure control. How will the two choices, we have to analyze simple Network pressure on the most disadvantaged constant, the water pipe network by QMAX reduced to Q1, pumps reduce speed, and water characteristic curve of A (unchanged) at the intersection point C, pump characteristic curve downward, network pressure on the most disadvantaged H0. And the pump outlet pressure constant pressure control, Ha unchanged, reduce water consumption by QMAX QI and Ha to pay to point B, water characteristic curve upward A through B,the network most disadvantaged Hb pressure into points. Hb-H0 lift the poor namely, energy waste, so I chose the most disadvantaged network points for the smallest head pressure control parameters. Formation pressure on the closed-loop control system, making the pump speed and PID regulator set pressure match, achieve maximumenergy-saving effect, but the constant pressure to achieve the purpose of water supply.The converter and put into operation after the commissioning of the system to ensure optimum operation of the state means necessary. According to the inverter load inertia size of the start and stop the motor when the time is not the same, Set time is too short to be accelerated when the inverter overcurrent, overvoltage decelerating protection; Set time will lead to excessive speed converter running in the system become regulate slow, delayed response, contingency ability is poor. Yi system at the state short-term instability. To protect the converter is not tripping, the scene of many of them usingconverter increases deceleration time setting too long, the problems they bring very easily be the appearance of the normal equipment and hide, but the converter operating in less-than-optimal state. So the scene when used according to the load driven by a different nature, testing out the permission of the shortest load increases deceleration time, setting. For the pump motor, plus deceleration time in the choice between 0.2-20 seconds.3.CONCLUSIONS AND OUTLOOKes the frequency changer - PLC constant pressure water supply installment to have following several merits:A:The electricity saving benefit is high. The traditional water pump electrical machinery uses the large capacity electrical machinery, is constant with the valve control water volume, creates the electrical energy waste.Frequency conversion system, regardless of the operational parameter how, the electrical machinery efficiency can't reduce, theelectrical machinery power factor can obtain the enhancement.B:Moves is reliable, is stable. In the system core part - frequency conversion velometer itself reliability is very high, in the ordinary circumstances may the long-term usage100,000/Above h. The system also selects the soft start method, does not have the electrical impact, does not pollute the electrical network, moreover frequency changer bringing owes presses, the pressure, the overflow, the overload, superheat as well as loses speed and so on each kind of protection function. The system adopts damping filter processing to the pipe network fluctuation of pressure, the water supply constant pressure precision is high, usually can control in the 0.002Mpa scope.C:The structure is simple, the operation is simple. The installment control system uses the integration rate to be high, necessary plan nimble diverse, obtains water pump movement each kind of combination by the programmablecontroller. The velocity modulation scope is broad, to water volume change adaptiveness.D:The service life is long, the automaticity is high, does not need the human to safeguard, maintains the quantity to be few.Above system the effect is remarkable in the actual application, if brings in PLC and the frequency changer the programmer the function integration, potential becomes somespecial-purpose frequency changers, such system reliability and the toughness big enhancement, the application is simpler, the system total cost also can drop.2.May foresee: The future frequency conversion technology will be able to develop to the below direction:(1) high performanceThus including internal leveling circuit, the contravariant electric circuit all use the high frequency PWM electric circuit to cause the input, the output all are sine waves; Uses themulti-densification regarding the large capacityfrequency changer and many machine is parallel; Reduces frequency changer own loss, the realization high efficiency; Realizes autotune or from the optimization, the remote control and controls far; Even more faces the user, further enhances the workability and Maintainability: Turns towards, the featherweight development small, as well as reduces the cost and so on.(2) intellectualizationIncluding two aspects: Reduces the hardware as far as possible, realizes the hardware software; Uses the intelligent electric power electronic device and other intellectualized part. The integration is the intellectualized foundation.(3) entire digitizationIn recent years, each kind of modern control theory, the expert system, the fuzzy control and the neuron control and so on all were the development hot spots, will cause the electric power electronic control technological development to a brand-new stage. Estimated the21st century entire numerical control the application will be more widespread thoroughly, even will substitute for the simulation control.(4) systematizationFrequency conversion technology development is inseparable from the development of related technologies, frequency conversion technology development in the 21st century is to grid, regulators, rely machine, electric motors, production machinery and control systems as a whole, from the system for consideration.3. The features of PLC3.1 FeaturesThe main difference from other computers is that PLCs are armored for severeconditions such as dust moisture heat cold and have the facility for extensiveinput/output I/O arrangements. These connect the PLC to sensors and actuators.PLCs read limit switches analog process variables such as temperature and pressureand the positions of complex positioning systems. Some use machine vision. On theactuatorside PLCs operate electric motors pneumatic or hydraulic cylindersmagnetic relays solenoids or analog outputs. The input/output arrangements may bebuilt into a simple PLC or the PLC may have external I/O modules attached to acomputer network that plugs into the PLC.3.2 System scaleA small PLC will have a fixed number of connections built in for inputs andoutputs. Typically expansions are available if the base model has insufficient I/O.Modular PLCs have a chassis also called a rack into which are placed modules withdifferent functions. The processor and selection of I/O modules is customised for theparticular application. Several racks can be administered by a single processor andmay have thousands of inputs and outputs. A special high speed serial I/O link is usedso that racks can be distributed away from the processor reducing the wiring costs forlarge plants.3.3 User interfacePLCs may need to interact with people for thepurpose of configuration alarmreporting or everyday control. A simple system may use buttons and lights to interact with the user. Textdisplays are available as well as graphical touch screens. More complex systems use aprogramming and monitoring software installed on a computer with the PLCconnected via a communication interface.3.4 CommunicationsPLCs have built in communications ports usually 9-pin RS-232 but optionallyEIA-485 or Ethernet. Modbus BACnet or DF1 is usually included as one of thecommunications protocols. Other options include various fieldbuses such asDeviceNet or Profibus. Other communications protocols that may be used are listed inthe List of automation protocols.Most modern PLCs can communicate over a network to some other system suchas a computer running a SCADA Supervisory Control And Data Acquisition systemor web browser.PLCs used in larger I/O systems may have__________________________________________________peer-to-peer P2P communicationbetween processors. This allows separate parts of a complex process to haveindividual control while allowing the subsystems to co-ordinate over thecommunication link. These communication links are also often used for HMI devicessuch as keypads or PC-type workstations__________________________________________________。
PLC在恒压供水控制中的应用
PLC在恒压供水控制中的应用Water is essential for both n and daily life。
However。
if the water source is far away from the place where it is needed。
pipelines are XXX higher places。
there XXX water pressure is the water pump。
and the faster the water pump rotates。
the higher the water pressure it produces。
The XXX water pressure is to build a water tower。
where water is pumped into the tower when the pump is running。
and the water level in the tower is used to supply water when the pump is resting。
The water level in the water tower changes very little relative to the height of the tower。
which means that the water tower can maintain a basic constant water pressure in the supply XXX。
building a water tower requires financial resources。
and the water tower can also cause secondary n to the water.This XXX and fire water supply。
基于PLC的变频恒压供水系统设计
题目基于PLC的变频恒压供水系统设计英文题目Design of Variable Frequency ConstantPressureWater Supply System Based On PLC作者声明本人以信誉郑重声明：所呈交的学位毕业设计（论文），是本人在指导教师指导下由本人独立撰写完成的，没有剽窃、抄袭、造假等违反道德、学术规范和其他侵权行为。
文中引用他人的文献、数据、图件、资料均已明确标注出，不包含他人成果及为获得东华理工大学或其他教育机构的学位或证书而使用过的材料。
对本设计（论文）的研究做出重要贡献的个人和集体，均已在文中以明确方式标明。
本毕业设计（论文）引起的法律结果完全由本人承担。
本毕业设计（论文）成果归东华理工大学所有。
特此声明。
毕业设计（论文）作者（签字）：年月日本人声明：该学位论文是本人指导学生完成的研究成果，已经审阅过论文的全部内容，并能够保证题目、关键词、摘要部分中英文内容的一致性和准确性。
学位论文指导教师签名：年月日摘要本论文根据中国城市小区的供水要求，设计了一套基于PLC的变频调速恒压供水系统,并利用组态软件开发良好的运行管理界面。
变频恒压供水系统由可编程控制器、变频器、水泵机组、压力传感器等构成。
系统包含三台水泵电机，它们组成变频循环运行方式。
采用变频器实现对三相水泵电机的软启动和变频调速，运行切换采用“先启先停”的原则。
压力传感器检测当前水压信号，送入PLC与设定值比较后进行PID运算，从而控制变频器的输出电压和频率，进而改变水泵电机的转速来改变供水量，最终保持管网压力稳定在设定值附近。
通过工控机与PLC的连接，采用组态软件完成系统监控，实现了运行状态动态显示及数据、报警的查询。
变频恒压技术集低成本、高度自动化、高稳定性、高可靠性、高效节能、方便调试等优点于一身。
当前变频恒压控制正逐步走向全数字化控制和各种体系化的发展方向。
追求高度智能化、系列化、标准化，在将来给水系统设备将占领城镇各个楼层、各个用水单位的绝大部分市场。
基于PLC的变频恒压供水系统设计
摘要随着科学技术的迅速发展, 传统供水方式存在着出水量时大时小、耗能大的各种缺点日益突显。
为了提高供水质量, 随着科学技术的迅猛发展,我们的设备也随着更进，我搜索文献学习后设计了一种基于PLC的恒压供水系统, 它及先进的自动化控制技术、变频调速技术、以及通信技术为一体,采用PID闭环控制的方式大大提高供水的稳定性及可靠性。
该系统的基本原理是用压力传感器检测管网中的水压，把测得的压力传入到PLC内部的PLD模块后进行计算，得出偏差信号再进行调整输出频率，从而调节水泵的转速，使得管网的水压稳定在设定值。
关键词：PLC 恒压供水变频调速Design of Constant Pressure Water Supply SystemBased on PlcAbstract：With the rapid development of science and technology, the traditional water supply method is unstable, energy consumption and other shortcomings become increasingly prominent.In order to improve the quality of water supply, this paper designs a constant pressure water supply system based on PLC.which integrates advanced automatic control technology, frequency conversion speed control technology and communication technology in one, using PID closed-loop control mode, greatly improving the water supply stability Sex and reliability.The basic principle of the system is to use the pressure sensor detects the water pressure in the pipe network and feeds back the measured pressure to the PLC inside the PID module to calculate the deviation signal to adjust the frequency of the inverter output frequency, thus adjusting the pump speed, So that the pipe network pressure stability in the vicinity of the set value.Keyword：PLC ，Constant Pressure Water Supply ，Frequency Control目录1 引言 (1)2 恒压供水系统的选择 (2)3 PID控制 (3)4 恒压供水系统的特性分析 (4)5 PLC恒压供水系统设计方案 (5)5.1 信号检测 (5)5.2 PLC恒压供水系统的主要控制部分 (5)6 系统的整体设计及工作原理 (6)6.1 变频恒压供水系统硬件设计 (8)6.2变频恒压供水系统软件设计 (11)7 供水系统的分类 (14)7.1无负压 (14)7.2供水系统无塔 (16)7.3供水系统超静音 (18)7.2供水系统屏蔽式 (19)7.2供水系统双模变频 (19)结语 (22)致谢 (23)参考文献 (24)1.引言在我们的日常生活中，供水系统在用水需求较高时，供水管道中的水压会出现下降的情况，不能再满足用户的生活需求；用水量较低时，供水管道中的水压将升高，远超出了用户的需求，这种情况不仅浪费珍贵的水能源，而且还会对供水管道及用水设施造成损坏。
基于PLC和变频器的恒压供水泵站系统设计
供 电 电压 和频 率 ， 制 电机 转速 以调 节流量 实现 了恒压供 水参 数的 自动控 制 ， 控 保证 了供 水 系统 随时 维持在 最佳运 行状 况。
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基于PLC和变频器恒压供水控制系统
基于PLC和变频器的恒压供水控制系统摘要：描述了plc和变频器组成的恒压供水控制系统的组成、结构及工作原理。
系统采用变频调速方式自动调节水泵电机的速度，改变了以往先启后停的方式，使系统能够自动和手动完成各个泵的启动、停止和无冲击切换，以及故障报警，使水压平稳过渡。
关键词：plc 变频器继电器 pid控制器the constant voltage based on plc and frequency converter supplies water of the control systemshou yifengyuyao city drainage company (zhejiang yuyao 315400) abstract：the article has described the constant voltage made up of plc and frequency converter supplies water of the composition,structure and operation principle of the control system.the system adopts frequency conversion to adjust the speed of the automatic water pump electrical machinery of speed way,changed the way that was suspended after opening in the past,make the system automatic and finishing the arrival of each pump,stopping and not assaulting switching over manually,and fault alarm,make the smooth transition of water pressure.keywords：plc；inverter；relay；pid controller1引言随着社会的发展和进步，城市高层建筑的供水问题日益突出。
基于PLC的变频恒压供水系统设计【文献综述】
方，就有变频器的存在。
变频恒压供水是在变频调速技术的发展之后逐渐发展起来的。
在早期，由于国外生产的变频器的功能主要限定在频率控制、升降速控制、正反转控制、起制动控制、起制动控制、压频比控制及各种保护功能。
应用在变频恒压供水系统中，变频器仅作为执行机构，为了满足供水量大小需求不同时，保证管网压力恒定，需在变频器外部提供压力控制器和压力传感器，对压力进行闭环控制。
从查阅的资料的情况来看，国外的恒压供水工程在设计时都采用一台变频器只带一台水泵机组的方式，几乎没有用一台变频器拖动多台水泵机组运行的情况，因而投资成本高。
随着变频技术的发展和变频恒压供水系统的稳定性、可靠性以及自动化程度高等方面的优点以及显著的节能效果被大家发现和认可后，国外许多生产变频器的厂家开始重视并推出具有恒压供水功能的变频器。
目前国内有不少公司在做变频恒压供水的工程，大多采用国外的变频器控制水泵的转速，水管管网压力的闭环调节及多台水泵的循环控制，有的采用可编程控制器(PLC)及相应的软件予以实现;有的采用单片机及相应的软件予以实现。
但在系统的动态性能、稳定性能、抗扰性能以及开放性等多方面的综合技术指标来说，还远远没能达到所有用户的要求。
3、供水系统变频设备变频器的发展水平是由电力电子技术、电机控制方式以及自动化控制水平三个方面决定的。
在现代自动化控制领域中，以现代控制论为基础，融入模糊控制、专家控制、神经网络控制等新的控制理论，为高性能变频调速提供了理论基础；16位、32位高速微处理器以及信号处理器和专用集成电路技术的快速发展，则为实现变频调速的高精度、多功能提供了硬件手段。
在我国，大约60%的发电量是通过电动机消耗掉的，因此，如何利用电机调速技术进行电机运行方式的改造以节约电能，一直受到国家和业界人士的高度重视。
我国电气传动产业始于1954年。
现在，我国约有200家左右的公司、工厂和研究所从事变频调速技术的工作，但自行开发生产的变频调速产品和国际市场上的同类产品相比，还有比较大的技术差距。
工业自动化专业毕业设计论文基于PLC的供水控制系统设计
基于PLC的供水控制系统设计DESIGN OF WATER TOWER LEVELCONTROLLING SYSTEM BASED ON PLC摘要在恒压无塔供水系统取得较大发展的今天，传统的水塔供水系统以其低廉的价格和操作的简便在工农业生产和日常生活中仍然具有广泛的应用，在对水压要求不高以及水位现场高度较低的情况下，以用水塔进行供水为主。
本系统采用西门子公司生产的S7-200系列可编程控制器作为控制核心，用液位传感器采集水塔现场的水位信号，通过文本显示器设定或显示相关参数，利用可编程控制器的继电器输出控制水泵对水塔供水或停水，使水塔水位保持在相对稳定的范围，保证工农业生产的顺利进行和日常生活中对用水的需求。
关键词过程控制PLC 水塔水位ABSTRACTIn the time of constant pressure without tower water systems have achieved a greater development, the traditional water tower water supply system for its low price and simplicity of operation in industrial and agricultural production and daily life is still widely used,in water pressure less demanding and water level in the scene at low altitudes, the main supply of water with a water tower. This system use Siemens S7-200 series programmable controller as its control unit,and use the signal level sensor to collect the water level of the water tower site, then through the text display to setting or display the parameters, the relay output of programmable controller to control pump the water tower water supply start or stop, make the water tower water level maintained at a relatively stable range, to makesure the smooth progress of the industrial and agricultural production and daily life in the demand for water.KEY WORDS process control PLC water level of tower目录中文摘要 .......................................................................................... 错误！未定义书签。
基于PLC的软启动变频双恒压无塔供水系统
基于PLC的软启动变频双恒压无塔供水系统孙立书【摘要】Aiming at the problem of short life of the motor on the traditional two-constant pressure water supply system without the tower, a new two-constant pressure water supply system without the tower was designed.Programmable logic controller ( PLC), soft starter and frequency control technology was used in the new two-constant pressure water supply system, so the smooth start will take place.Because there is no impact on the motor, the motor life was extended.The result shows that there will be more energy efficiency in the new water supply system than traditional water supply system, energy-saving rate of 17％ or more, and also excellent water quality and water supply reliability.%针对传统双恒压无塔供水系统电机使用寿命较短的问题,设计出了一种新型的双恒压无塔供水系统.新型双恒压无塔供水系统采用可编程逻辑控制器(PLC)、软启动器和变频器控制技术,其软启动器能够实现平滑启动、对电机无冲击,可以延长电机寿命.实践结果表明,新型供水系统比传统供水系统更节能,节电率17%以上,而且还能提高供水质量和供水可靠性.【期刊名称】《机电工程》【年(卷),期】2011(028)006【总页数】5页(P715-718,731)【关键词】可编程逻辑控制器;软启动器;变频器;双恒压;无塔;供水系统【作者】孙立书【作者单位】浙江东方职业技术学院,工程系,浙江温州325011【正文语种】中文【中图分类】TP39;TH390 引言在过去的双恒压无塔供水系统的电气设计中，人们常常采用基于PLC的“单台变频器控制多台水泵切换的控制系统”，以节约投资［1］。
基于PLC的变频恒压供水系统的设计
基于PLC的变频恒压供水系统的设计基于PLC的变频恒压供水系统的设计一、引言随着社会经济的发展和人民生活水平的提高，人们对供水系统的稳定性和高效性要求越来越高。
传统的水泵控制系统往往存在运行不稳定、能耗大、操作复杂等问题。
为了解决这些问题，本文将介绍一种基于可编程逻辑控制器（Programmable Logic Controller, PLC）的变频恒压供水系统的设计。
二、系统架构变频恒压供水系统是一种利用变频器（Variable Frequency Drive, VFD）控制水泵运行的系统，能实现根据水压需求自动调整水泵的转速，以保持恒定的供水压力。
该系统的基本架构如图1所示：[插入图1的系统架构图]图1 变频恒压供水系统的基本架构系统包含以下组成部分：1. PLC控制器：负责监测供水系统的状态和参数，并控制变频器的工作状态。
2. 变频器：通过调整水泵的转速，实现供水压力的恒定。
3. 传感器：用于测量供水系统中的压力、流量等参数，并将数据反馈给PLC控制器。
4. 水泵：根据PLC控制器的指令，通过变频器控制实现供水。
三、系统设计1. PLC程序设计PLC程序是整个系统的核心，它通过读取传感器的数据，计算供水压力的误差，并根据误差值控制变频器的输出频率，从而调整水泵的转速。
具体步骤如下：（1）读取传感器数据：PLC定时读取各传感器的数据，包括供水管道的压力、流量等参数。
（2）计算误差值：将实际压力值与设定的理想压力值进行比较，得到压力的误差。
根据误差的大小和方向，判断应增大或减小水泵的转速。
（3）控制变频器输出频率：PLC发送控制信号给变频器，调整输出频率，控制水泵的运行速度。
（4）循环控制：通过不断地监测和调整水泵运行的频率和转速，实现供水压力的恒定。
2. 变频器参数设置根据供水系统的实际需求，需要合理设置变频器的参数，以确保系统的稳定性和高效性。
主要包括以下参数：（1）负载类型：选择合适的负载类型，通常为泵类。
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Constant Pressure Water Supply System Based plcAbstract: Based one simple analysis of the methods for water supply used domestically and abroad, this paper discusses the principl e and system’s structure of automatic water supply system by using frequency conversion speed regulation in detail. Then the system’s advantages are discussed and some key problems that should be pay attention to designing are presented.Keyword: Frequency conversion speed regulation; water supply with stable pressure: PID regulator.1、ForewordAt present, supply water in residential area and life of the skyscraper of our country generally adopt the way common frequently. It has heavy energy consumption, high noise, and there has a great deal of questions in the source of water, such as secondary pollution etc. And it is a kind of comparatively ideal mode to adjust the water supply device controlled rapidly with frequency conversion .Entering the middle and later periods of the 1990s, as the speed technology of frequency conversion achieves more development becomes perfect, the way of the full-automatic constant pressure that based on this technology supplied water has already been widely used in the developed country, and is becoming riper.In recent years, authors has made some real work on rapidly to the transformation in frequency conversion supply water design and construction of control system, have accumulated some experience, and has formed the view on some questions. The reason why the energy-conserving principle frequency conversion of the water pump system of speed adjustment becomes popularized , is mainly because that it has a better energy- conserving result. To pump system of frequency conversion, the water pump after adjusting the speed has functional relation of the following:Q1/Q2 =n1/n2 (1)H1/H2 = (n1/n2)2(2)of the type. Q1, Q2 represents the flow before and after the speed for the water pump respectively; N1, n2 represents the rotational speed before and after the speed for the water pump respectively; H1, H2 represents the lift before and after the speed for the water pump respectively.According the above: H1/H2 = (f1/f2)ly real lift of a water pump is power the square of frequency in direct radio. Therefore changing the power supply frequency of the electrical machinery of water pump through the frequency converter can control supporting water pressure strength of the water pump. 2 constant pressures as Fig. 1 shows supply water of the automatically controlled frequency conversion water -supply system principle block diagram. P1 is the give pressure value, p2 for the actual pressure value had examined from the pipeline of the pressure sensor, PID regulator passes the error operation of the two value, and through controlling the frequency output of the frequency converter, thus make the pressure of the pipeline remain throughout on establishing value p1.This system can measure users' instantaneous water pressure adjust automatically , regulate the amount of quantity of supplying water and operation conditions of the electrical machinery in view of the above. Can according to give water pressure strength to set for and control pressure value which needed , make the equipment in the constant pressure state all the time, can know from load characteristic of electrical machinery axle power and its the third power of in direct radio rotational speed of electrical machinery mixed, that is p1/p2=(n1/n2)3. For example, as the frequency converter output frequency for 35Hz (establish as 50Hz at most), that is to say that the actual rotational speed is 70% o'clock of specified rotational speed, the power consumption of the governor is 0.73 =0.343, account for specified 35%. That is tosay , the water pump is always in constant pressure and turn the working state of matching the way into the flow , is it is it keep to exceed to dispel and backset current have work loss. Constant speed transfer with frequency conversion speed axle power change curve as Fig. 2 shows , relatively can know, it is the most obvious that frequency conversion adjusts the energy-conserving result of speed way.2、Case analysesConstant pressure is it regulate flow of water to the purpose to up to constant pressure through suiting well rapidly in frequency conversion to supply water, the goal that it controls finally is the water pressure. Controlling the target has non-linear, lagging characteristics. The quality of PID regulator performance , has determined the quality of the water -supply system to a great extent When the system is during the course of starting and stopping, or the pressure establishing value changes by a large margin , because there is a very great deviation within short time, no matter the control algorithm of PID regulator adopts the increment type or the position type, its total mark one will fetch the cistern , water pump group and complement the fittingsto form relevantly. The core of this system is that frequency conversion adjusts the speed switch board, it monitors the pressure of the pipe network in real time through the pressure sensor, and change into the electric signal and offer the frequency converter to make operation, through the controlling commonly of frequency converter, programmable controller PLC and relay array, adjust the system of supplying water rapidly after forming perfect full-automatic frequency conversion. Frequency converter is various in kinds, for instance the types, such as Mitsubishi, Fuji, three Kenya and ABB, etc. Generally often select the pumps, special-purpose series of air blower for use. Whether take Mitsubishi FR-A140E as an example, it except general function had of brand , there are the following characteristics : The inside adopts the intellectual power module of IPM, it is lowest to make the noise of the electrical machinery to reduce; Frequency converter, and work-frequency power can is it switch over to go on frequently, user is it is it start , stop through PLC and switch over the order automatically to input to need only, can conveniently through to lock movement switch over different water pump each other contactor, and does not need to design the tedious control procedure by oneself like the thing that in the past , this is one of this peculiar functions of frequency converter; Built-in instantaneous power cut starts and retries and starts the function , in a situation that nobody guarded,even if can be started by oneself after the frequency converter shuts down, totally realize with the operation of the automatic way. PID regulator available frequency converter of system this built-in value very heavy, this will store deviation in regulates. During the process of dispelling the deviation to regulate, must lead to the fact the system and present greater ultra mediation long-time vibration, can produce the serious integration saturation phenomenon also at the same time, thus influence the normal running of the equipment. Is it drop the influence to most low to want , should adopt PID control method that integration separate among controlling algorithm, in order to reach the anticipated result. After dealing with like this, can shorten the system and reach steady transition course time greatly System allocate two 11kW water pump support 600 over resident water. Two pump offer large peak flow most when working at the same time, single platform meet the small flow and supply water at night. In addition all water pumps can run by way of frequency conversion, can circulate way soft to start, in this way, can reduce the impact to the electric wire netting and pipe network. What merits attention is two pump when frequency conversion and worker are switched over frequently, have procedure it locks to be enough each other only, outputting must adopt machinery to interlock the contactor, can avoid the situation that two contactors close at the same time in the twinkling of an eye in this way, so as not to short out in twinkling of an eye causing power. Pressure sensor P monitors the size of the water pressure signal in real time, the signal is dealt with by PID, input it to the frequency converter. At the small flow, water pump electrical machinery 1M turn round (whether 1KM1 is it shut to suck), and through feedback password change his rotational speed constantly, it is invariable in order to keep the pressure; In case of large flow , compare frequency conversion by pressure circuit send out through PLC " constant/changed switch over frequently" " operate and interlock " the order, machinery interlocks the contactor ( 2KM2 in 2KM (2KM1 +2KM2 ), contactor 3KM have the electricity. At this moment, electrical machinery 2M is started by way of frequency conversion, 1M is switched over and run at full speed frequently to run. In this way, this system can maintain water consumption on a invariable pressure all the time. Built up in the aforesaid district initial stage, supply water and adopt the way frequently of workers, because of energy consumption being heavy dependability is bad, the household reflects strongly. Use instead after frequency conversion supply water, installation total capacity reduce 25% than original equipment, economize on electricity the index is close 30% synthetically actually, the result is remarkable.3、Several questions while apply are in case of great majorityThe environment for use of the scene is comparatively abominable. Though frequency converter has very strong protection functions itself, such as owe keep , excessive pressure , is it flow to pass, electric current amplitude limiting is it make exactly to choose, overload, overheated lacking looking , shorting out and disconnected ink protect the function But must prevent trouble before it happens . Through using finding, two kinds of brands of Mitsubishi, Fuji, because has fully considered various kinds of abominable running environment in design andmanufacture. The dependability and service life under the same condition are higher than some brands. One small city of mountain area of west place in Hubei in Hubei, average 1200m above sea level, the humidity on the high side of long-term most of the time (about 80%), the sulfur dioxide is seriously polluted, a set of frequency conversion that one factory produces supplies water of the equipment, because has not considered above-mentioned factors, less than one year, the relevant parts of the equipment are corroded seriously. And the like product which we designed, installed in the same area, because has fully considered the situations of different difference, on the selecting types of the equipment and component, have adopted the ship standard. Through the use of more than two years, ran well, stood the tests of different sternness. Find in using actually, the frequency converter itself is that a strong interference takes place in the source, will often influence the normal running of the equipment. Especially when the low rotational speed of the water pump operates, the frequency shown on the frequency converter does not correspond to actual operation frequency. Generally there are two kinds of spread ways to interfere: The circuit bunch is disturbed and space radiation is interfered. Can take the corresponding measure to solve according to the actual conditions of the scene. For example is it strain wave and absorb the return circuit to increase to programmable power end of controller, PID regulator introduction of unit output sure to have reliable shielding, link frequency converter, ground terminal of electrical machinery with earth stake firmly, control the line and motive force line leave certain distance, in order to strengthen and resist the electromagnetic ability to interfere. Only in this way, can make system keep the long and steady working state in high temperature, humidity, mould, strong harsh terms of interfering etc.4、ConclusionsAre by way of adjusting the speed as the central water supply in frequency conversion, the result is obvious to economize on water, economize on electricity, can be extensively suitable for 20-10000 residents the biotope, skyscraper, hotels and restaurants, fire control or district pressurize and supply water, it is ideal facilities that the medium and small- scale waterworks supplied water too. Its amount of water quality supported is high, the economic benefits are obvious, the social benefit is enormous, with the development of national economy and constant improvement of the living standards of the people, it is sure to be used and popularized progressively in our country5、List of referencesZhang Wanzhong, Zhu Jie, Wang Mingquan. A kind of new-type frequency conversion constant pressure supplies water of the plan of design of the pump station. Electrical age, 1999 (10): 22-232Liu YingChun. Principle design of the sensor and application. Beijing: University of Science and Technology of the national defense publishing Press, 1989.59-623Lu Guangda. Electric installation project manual of the building. Beijing: The electric publishing house of water conservancy, write the group in 1995.222- 2244"Theautomatic projecting ". Give and drain off water the automatic project. Beijing: The electric publishing house of water conservancy, 1997.301-312。