【正文】 畢 業(yè) 設(shè) 計(jì) 題目： 恒壓變頻供水系統(tǒng)設(shè)計(jì) 學(xué) 生： 學(xué) 號(hào)： 學(xué) 院： 電氣與信息工程學(xué)院 專 業(yè)： 電氣工程及其自動(dòng)化 指導(dǎo)教師： 2021 年 6 月 10 日 I 恒壓變頻供水系統(tǒng)設(shè)計(jì) 摘 要 隨著時(shí)代的進(jìn)步和社會(huì)的發(fā)展，大家對(duì)于用水質(zhì)量的要求越來越高，而我國又是一個(gè)水資源嚴(yán)重短缺的國家，所以對(duì)于供水系統(tǒng)設(shè)備的先進(jìn)性、自動(dòng)化程度和性能的要求都越來越高。恒壓變頻供水系統(tǒng)的應(yīng)用已經(jīng)成為了必然趨勢。 本論文 設(shè)計(jì)根據(jù)陜西科技大學(xué)供水系統(tǒng) 的 供水要求，設(shè)計(jì)了一套基于 PLC的變頻調(diào)速恒壓供水系統(tǒng)。 本系統(tǒng)由可編程邏輯控制器、 2臺(tái)軟啟動(dòng)器、 2臺(tái)變頻器、 7臺(tái)水泵電機(jī)組成，其中 1臺(tái)是夜間低壓狀態(tài)時(shí)使用，剩下的 6臺(tái)水泵電機(jī)組成循環(huán)運(yùn)行方式。設(shè)備運(yùn)行時(shí)，壓力傳感器檢測當(dāng)前水壓信號(hào)，將管網(wǎng)水壓信號(hào)轉(zhuǎn)變成電信號(hào)送入 PLC，由 PLC與設(shè)定值比較后進(jìn)行 PID運(yùn)算，再由 PLC控制著變頻器輸出不同頻率的電源，從而改變水泵電機(jī) 的 轉(zhuǎn)速來改變供水量， 最終保持管網(wǎng)壓力穩(wěn)定在設(shè)定值附近。論文詳細(xì)介紹了各主要器件的選型，連接方式，運(yùn)行原理，以及系統(tǒng)的軟件設(shè)計(jì)。其中著重的分析了程序的 主要 設(shè)計(jì)方法，講述了 供水系統(tǒng) 總體的設(shè)計(jì)思路。 關(guān)鍵詞 ：變頻調(diào)速，恒壓供水，變頻器， PLC IIDesign of Variable Frequency Constant Pressure Water Supply System ABSTRACT With the progress of the times and the development of the society,everyone for using the water quality requirements more and more high, furthermore China is a serious shortage of water resources in the country,so the water supply system equipment advanced, degree of automation and performance39。s requirements are getting higher and higher. Variable frequency constant pressure water supply system has bee an inevitable trend. This paper designs a set of PLC based variable frequency speed regulation constant pressure water supply system. The system consists of a programmable logic controller, 2 soft starters, 2 converters, 7 pump motors. One is the use of low voltage state at night, the rest of these are used to be cyclic operation mode. In the operation of the system by the pressure sensor measured the pipeline pressure, the pressure and expectation values are pared, after that by the PLC control converter output frequency of different power, and then change the speed of the pump motor to track the desired value of the water pressure. This paper introduces how to select the main ponents, connection mode, operation principle, and the software design of the system. The emphasis is on the analysis of the program design method, describes the overall design ideas. Key words: variable frequency speed regulation, constant pressure water supply, converter, PLC III 目 錄 摘要 .................................................................................................................................................................................. I ABSTRACT.................................................................................................................................................................. II 1 緒論 ............................................................................................................................................................................ 1 選題背景 ....................................................................................................................................................... 1 選題依據(jù) ....................................................................................................................................................... 1 國內(nèi)外發(fā)展概況 ......................................................................................................................................... 2 設(shè)計(jì) 內(nèi)容及要求 ......................................................................................................................................... 3 2 恒壓變頻供水系統(tǒng)的方案設(shè)計(jì) ........................................................................................................................... 4 系統(tǒng)的基本工作原理 ................................................................................................................................ 4 本課題研究的對(duì)象 ..................................................................................................................................... 4 控制方式的選擇 ......................................................................................................................................... 5 系統(tǒng) 原理與 組成 ......................................................................................................................................... 6 系統(tǒng)的組成及原理圖 .................................................................................................................... 6 變頻控制 原理 .................................................................................................................................. 7 系統(tǒng)水泵切換控制分析 ................................................................................................................ 8 3 恒壓變頻供水系統(tǒng)的硬件設(shè)計(jì) ........................................................................................................................... 9 系統(tǒng)主要設(shè)備電路的設(shè)計(jì) ....................................................................................................................... 9 PLC的設(shè)計(jì) ....................................................................................................................................... 9 變頻器的設(shè)計(jì) ................................................................................................................................ 11 軟啟動(dòng)器的設(shè)計(jì) ........................................................................................................................... 16 系統(tǒng)控制電路的設(shè)計(jì) .............................................................................................................................. 18 4 恒壓變 頻供水系統(tǒng)的軟件設(shè)計(jì) ......................................................................................................................... 20 主程序循環(huán) 流程圖 ................................................................................................................................... 20 系統(tǒng)上電 步驟 ...............................................................................................................