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《小型水廠恒壓供控制系統(tǒng)設(shè)計(jì)》由會(huì)員上傳分享，免費(fèi)在線閱讀，更多相關(guān)內(nèi)容在學(xué)術(shù)論文-天天文庫。
1、SHANDONGＵＮＩＶＥＲＳＩＴＹＯＦＴＥＣＨＮＯＬＯＧＹ畢業(yè)設(shè)計(jì)說明書小型水廠恒壓供水控制系統(tǒng)設(shè)計(jì)學(xué)院：電氣與電子工程學(xué)院專業(yè)：自動(dòng)化學(xué)生姓名：李曉粉學(xué)號(hào)：0812205761指導(dǎo)教師：李素玲2012年6月中文摘要摘要隨著社會(huì)的飛快發(fā)展，城市建設(shè)規(guī)模的不斷擴(kuò)大，工業(yè)化化水平的不斷提高，人們生活水平的不斷提高，人們對(duì)城市供水的質(zhì)量、數(shù)量、穩(wěn)定性提出了更高的要求。本論文根據(jù)小型水廠的工藝特點(diǎn)與要求，設(shè)計(jì)了一套基于PLC的變頻恒壓供水控制系統(tǒng)。該系統(tǒng)主要由PLC、變頻器、水泵機(jī)組、壓力變送器、液位變送器等構(gòu)成。系統(tǒng)有六臺(tái)
2、水泵電機(jī)，一臺(tái)大功率水泵電機(jī)用變頻器啟動(dòng)，變頻調(diào)速運(yùn)行，另一臺(tái)大功率水泵電機(jī)備用，另外四臺(tái)電機(jī)順序工頻運(yùn)行。壓力變送器檢測當(dāng)前水壓信號(hào)，送入PLC與設(shè)定值比較后進(jìn)行PID運(yùn)算，從而控制變頻器的輸出電壓和頻率，進(jìn)而改變水泵電機(jī)的轉(zhuǎn)速來改變供水量。當(dāng)變頻器的頻率輸出升到48Hz時(shí)，管網(wǎng)壓力還是過低，這時(shí)要開啟工頻泵；當(dāng)變頻器的頻率輸出降到20Hz時(shí)，管網(wǎng)壓力還是過高，這時(shí)需要停止工頻泵。最終保持管網(wǎng)壓力穩(wěn)定在設(shè)定值附近。關(guān)鍵詞：變頻調(diào)速,PLC,恒壓供水IAbstractAbstractWiththerapiddevelo
3、pmentofthesociety,thescaleofcityconstructionisexpanding,andtheindustrializationlevelincreases,people’sstandardoflivingisrisingconstantly,sopeoplearecontinuouslyimprovingtherequirementstothequalityofwatersupplying,reliabilityofwatersupplysystemandenergysaving.Acc
4、ordingtotherequirementofwatersupply,thispaperdesignsasetofwatersupplysystemoffrequencycontrolofconstantvoltagebasedonPLC..ThesystemconsistsofPLC,frequencyregulator，unitsofpumps,waterleveltransducer,pressuretransducerandsoon.Therearesixpumpsmotorsinthissystem.One
5、ofthebiggestmotorsisstartedwiththefrequencyregulator,theotherbiggestisalternate,anotherarestartedinsequence.PressureregulatordetectsthewaterpressuresignalandthenputsitintothePLCtocomparewiththesetvalue,thenthePIDoperatessoastocontroltheoutputvoltageandfrequencyo
6、ffrequencyregulator,andchangethespeedofthepumpmotortochangethesupplyquantity.Whentheoutputofthefrequencyregulatorisupto48Hz,butthepipepressureistoolow,theindustrialfrequencypumpwillbestartedatthistime;Whentheoutputofthefrequencyregulatorisdownto20Hz,butthepipepr
7、essureistoohigh,theindustrialfrequencypumpwillbestoppedatthistime.Ultimatelythepressureofthepipenetworkremainsconstantaroundthesetting.Keywords:variablefrequencyspeed-regulating,PLC,constant-pressurewatersupplyII目錄目錄摘要............................................
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