【正文】 個(gè) 水 箱 需 要 維 持 一 定 的 水 位 ， 該 水 塔里 的 水 以 變 化 的 速 度 流 出 。研究設(shè)計(jì)的基于 PLC 控制的水塔水位 PID 供水系統(tǒng),以西門子公司的 S7200系列中 PLCCPU226 為基礎(chǔ)，結(jié)合模擬量模塊 EM23液位傳感器、輸入控制液壓閥、輸出控制液壓閥等，組成一個(gè)基于 S7200 系列中 PCLCPU226 的水塔水位控制系統(tǒng)，能完成邏輯控制、水位調(diào)節(jié)和數(shù)據(jù)采樣等功能,實(shí)現(xiàn)對(duì)水塔的水位進(jìn)行控制及檢測(cè)。關(guān)鍵詞： 可編程控制器 PLC，水塔水位，PID 控制 WATER TOWERS PID CONTROL SYSTEM DESIGNABSTRACTWater supply is an important industry of the people39。s living standards, urban water supply to a higher demand, there is a need to maintain a certain water tank water level, the water towers in order to change the speed of the outflow. This requires a liquid input control valve to the different speeds of water towers in order to maintain the water level changes, so that continuous water towers. In the system, only the use of proportion and integral control, the loop gain and time constant can be calculated through the preliminary engineering, but also the need for further adjustments to achieve optimal control. System startup, shut down the outlet for moving the liquid control valve control input, so that the water level reached 75% of full water level, and then open the outlet, while the liquid input control valve to switch from manual to automatic mode. This switch from a digital control input. The design of Siemens S7200 series PLCCPU226based light simulation module E235, liquid level sensors, type of hydraulic control valves, hydraulic valves, such as output control, based on the formation of a S7200 series PCL CPU226 water level control system of the towers, the water level of the towers to monitor and control. Keywords: Programmable Logic Controller PLC, Water Towers, PID Control目　錄前　 言 ...........................................................................................................1第 1 章 水塔水位自動(dòng)控制系統(tǒng)的概述 ...................................................2 水位控制系統(tǒng)現(xiàn)狀與發(fā)展 ............................................................2 水塔水位自動(dòng)控制系統(tǒng)的組成 ....................................................2 水位控制系統(tǒng)效率及運(yùn)行模式分析 ............................................3第 2 章 PLC 結(jié)構(gòu)和工作原理 ..................................................................4 PLC 組成與基本結(jié)構(gòu) ...................................................................4 PLC 的系統(tǒng)結(jié)構(gòu) ..................................................................4 PLC 的基本工作原理 ..........................................................5 PLC 的主要應(yīng)用 ...........................................................................6 S7200 系列可編程控制器 ..........................................................6 S7200 PLC 系統(tǒng)組成 ..........................................................7 S7200 系列 PLC 元件功能 .................................................7 PID 控制器簡(jiǎn)介 ............................................................................9 PID 控制器的結(jié)構(gòu)及原理 ...................................................9 數(shù)字式 PID 控制 ................................................................10 數(shù)字式 PID 控制的實(shí)現(xiàn) ....................................................12第 3 章 水塔水位控制系統(tǒng)方案設(shè)計(jì) .....................................................14 系統(tǒng)的工作原理 ..........................................................................14 設(shè)計(jì)分析 .............................................................................14 可行性試驗(yàn) .........................................................................15 可行性分析 .........................................................................16 水位閉環(huán)控制系統(tǒng) ......................................................................16 PLC 的選擇 ........................................................................17 供水的控制方法 .................................................................18第 4 章 PLC 中 PID 控制器的實(shí)現(xiàn) ........................................................20 PID 算法 ......................................................................................20 PID 應(yīng)用 ......................................................................................21 PLC 實(shí)現(xiàn) PID 控制的方式 .........................................................21 PLC PID 控制器的實(shí)現(xiàn) ..............................................................22 PID 指令及回路表 ......................................................................24第 5 章　 系統(tǒng)硬件開發(fā)設(shè)計(jì) .....................................................................26 可編程控制器的選型 ..................................................................26 EM235 模擬量模塊 .....................................................................28 EM235 的安裝使用 ............................................................29 EM235 的工作程序編制 ....................................................29 硬件連接圖 ..................................................................................30 控制系統(tǒng) I/O 地址分配 ..............................................................30第 6 章 系統(tǒng)軟件應(yīng)用設(shè)計(jì) .....................................................................31 水位 PID 控制的邏輯設(shè)計(jì) .........................................................31 梯形圖編程 ..................................................................................35 控制程序 ......................................................................................38 聯(lián)機(jī) ..............................................................................................39結(jié) 論 .........................................................................................................40謝 辭 .........................................................................................................41參考文獻(xiàn) .....................................................................................................42附　 錄 .........................................................................................................43外文資料翻譯 .............................................................................................46前　言在工業(yè)生產(chǎn)中，電流、電壓、溫度、壓力、液位、流量、和開關(guān)量等都是常用的主要被控參數(shù)。在社會(huì)經(jīng)濟(jì)飛速發(fā)展的今天，水在人們正常生活和生產(chǎn)中起著越來(lái)越重要的作用。因此給水工程往往成為高層建筑或工礦企業(yè)中最重要的基礎(chǔ)設(shè)施之一。就目前而言，多數(shù)工業(yè)、生活供水系統(tǒng)都采用水塔、