基于PLC的恒壓供水控制系統(tǒng)設計

1、基于PLC的恒壓供水控制系統(tǒng)設計摘 要隨著社會經(jīng)濟的迅速發(fā)展，人們對供水質(zhì)量和供水系統(tǒng)可靠性的要求不斷提高；再加上目前能源緊缺，利用先進的自動化技術(shù)、控制技術(shù)以及通訊技術(shù)，設計高性能、高節(jié)能、能適應不同領域的恒壓供水系統(tǒng)成為必然趨勢。本論文根據(jù)中國城市小區(qū)的供水要求，設計了一套基于PLC的變頻調(diào)速恒壓供水系統(tǒng)。由變頻器、PLC、PID調(diào)節(jié)器和組成控制系統(tǒng)，調(diào)節(jié)水泵的輸出流量。電動機泵組由三臺水泵并聯(lián)而成，由變頻器或工頻電網(wǎng)供電，根據(jù)供水系統(tǒng)出口水壓和流量來控制變頻器電動機泵組的速度和切換，使系統(tǒng)運行在最合理狀態(tài)，保證按需供水。本文介紹了采用PLC控制的變頻調(diào)速供水系統(tǒng)，由PLC進行邏輯控制，由

2、變頻器進行壓力凋節(jié)。再經(jīng)過PID運算，通過PLC控制變頻與工頻切換，實現(xiàn)閉環(huán)自動調(diào)節(jié)恒壓變量供水。運行結(jié)果表明，該系統(tǒng)具有壓力穩(wěn)定，結(jié)構(gòu)簡單，工作可靠等特點。關鍵詞：變頻調(diào)速 ；恒壓供水；PID調(diào)節(jié)；PLCWater Supply Control System of Constant Pressure Based on PLC顯示對應的拉丁字符的拼音ABSTRACTWith the rapid development of social economy； it demands the better of water supply' s quality and reliability o

3、f water supply system. Meanwhile energy resources are seriously lack. So it is inevitable tendency to design water supply system which has high function and saves on energy well， with help of advanced technique of automation， control and communication. At the same time this system can adapt differen

4、t water supply fields.According to the requirement of China's urban water supply, this paper designs a set of water supply system of frequecey control of constant voltage based on PLC. It is consist of the variable frequency and speed regulation， PLC， PID control system for the control system. I

5、t controls the outcome of the pumps. The generator pumps are consist of parallel three pumps， and the power come from variable frequency and speed regulation or power grid. According to the water supply of constant pressures outcome water press and flux， the control system control the variable frequ

6、ency and speed regulation， parallel pumps speed and cut over， cause the system move in the best rational situation， assure according to wants supply water. This design has many merits such as save energy.In this paper，the control principle of VVVF providing-water system is introduced，we use PLC to c

7、arry on logic control and use inverter to modulate pressureThrough PID control principle .we realize Closed-loop control in VVVF Providing-water SystemThe result indicates that the system has the stable pressure，simple structure，and reliable workKey words：variable frequency and speed regulation；wate

8、r supply of constant pressure；PID control system；PLC目 錄論文總頁數(shù)：53頁1 引言11.1 課題背景及意義11.2 供水技術(shù)及其發(fā)展11.3 恒壓供水系統(tǒng)國內(nèi)外研究現(xiàn)狀21.4 可編程控制器的發(fā)展及應用31.5 本文主要內(nèi)容42 恒壓供水系統(tǒng)介紹52.1 當前恒壓供水方案比較52.2 恒壓供水系統(tǒng)節(jié)能原理62.3 變頻器介紹82.3.1變頻器的基本結(jié)構(gòu)82.3.2 變頻器的分類及工作原理92.3.3 變頻器的操作方式及使用92.3.4 變頻器調(diào)速原理102.4 可編程控制器112.4.1 可編程控制器的定義112.4.2 可編程控制器的組成

9、112.5 供水系統(tǒng)中的水錘效應123 變頻恒壓供水系統(tǒng)方案設計133.1 變頻恒壓供水系統(tǒng)構(gòu)成133.2變頻恒壓供水系統(tǒng)運行流程153.3 水泵切換條件分析163.4 泵站的設置及系統(tǒng)控制要求173.5 控制系統(tǒng)地址分配174 變頻恒壓供水系統(tǒng)硬件設計194.1 PLC及其擴展模塊194.2 變頻器204.3 水泵機組224.4 壓力傳感器224.5 液位變送器224.6 泵自動/手動控制設計235 變頻恒壓供水系統(tǒng)軟件設計255.1 系統(tǒng)軟件設計分析255.2 系統(tǒng)軟件設計265.2.1系統(tǒng)初始化模塊275.2.2 增、減泵判斷和相應操作模塊285.2.3 水泵的軟啟動模塊285.2.4 各水泵變頻運行控制模塊295.2.5 各水泵工頻運行控制模塊305.2.6 報警及故障處理模塊305.3 系統(tǒng)程序編制316 系統(tǒng)仿真326.1 數(shù)字PID控制技術(shù)326