SystemstructureandcontrolschemesystemdesignfeaturesThecontrolsystemofventilationunitswithcentrifugalactivationofinterlockingandover-temperatureprotection.Andconventionalrelayscomparedtotheimplementationoftheventilationsystem,PLCsystemhasalowfailurerate,highreliabilityandwiringissimple,easymaintenanceandmanyotheradvantages,PLCcontrolfunctionssothatthventilationsystemsgreatlyenhancethedegreeofautomation,reducingthelaborjobsintensity.PLCandfrequencyconverterwiththeuseofairpressuretransmitter,allowingthesystemtocontrolthesecurity,reliability,greatlyimproved,butalsorunthefansignificantlyreducethefailurerate,notonlysavesenergybutalsoimprovetheoperationrateofequipment.Mineventilationsystemtomeettherequirementsofautomaticcontrolsystemthespecificdesignrequirementsareasfollows:(1)Thissystemprovidesmanual/automaticmodeofthetwo,withastateofalarmdisplayandfeaturessuchasfaults.(2)AnalogPIDoperatorviapressureinput,outputanalogconvertercontrol.(3)Intheautomaticmode,whenthedownholepressurebelowthesetpressurelimit,twosetsoffanswillberunningtoworkatthesametime,atthesametimeandissuedinstructionsandalarmsignals.(4)Analoginputgas,whenthegasconcentrationisgreaterthantheupperlimitofalarmsettings,andreporttothepolicetogivedirections.Whenthegasconcentrationisgreaterthantheupperlimitofpowersettings,PLCwillcutoffthefaceandwindpowergeneratingunitstopreventthegasexplosion.(5)Theuseoftemperaturesensorsmeasuredtemperatureorthewindbearingunitstatortemperature,bearingtemperatureorwhenthestatortemperatureexceedsthesetalarmontheline,givedirectionsandwarningsignals.Whenthestatortemperatureorthewindbearingtemperatureexceedsthesettemperatureofthelineunitconversion,PLCwillcutofftheinstructionsandalarmsignalandautomaticallycutofftheairunitiscurrentlyrunninginautomaticmodeandcanautomaticallyaccessanotherrunTyphoonunit,ifinthehanddynamicmanner,staffmanuallyswitch1.(6)Inordertopreventfatiguecentrifugalfanoperationinanystate,setthefantoruninatotaltimewillautomaticallyswitchtoanotherunitoperationtyphoon.systemarchitectureandprogramVentilationcontrolsystemismainlycomposedof2setsofcentrifugalfans,centrifugalfanseachhavetwomotors,eachmotordrivesasetoffanfilms,twofilmsontherotatingfanandasetofwindsuction,agrouptoincreasewindspeed,forthewindtocarryoutunderground.Undergroundairvolumeinaccordancewiththedifferent,usingdifferenttypesoffans.Thedesignof245kWfanasanexample,theselectionofaS72200PLC,theairpressuresensorandtransducer,suchastheformationofacompleteclosed-loopcontrolsystem.Includingcontactors,intermediaterelays,thermalrelays,MineExplosion-proofmagneticstarter,circuitbreakerprotectionofelectricalsystems,electricalandPLCtoachieveeffectiveprotection,aswellasmotorcontrolswitch.PLCcontrolsystemwiththefanmotortostartandrun,monitor,interlockandover-temperatureprotection.PLCandwiththeuseofairpressuretransmitter,allowingthesystemtocontrolthesecurity,reliability,greatlyimproved,butalsorunthefansignificantlyreducethefailurerateandimprovetheoperationrateofequipment2.Forcoalmineventilationsystemtomeettherequirementsofautomaticcontrol,designofcontrolprogramsisasfollows:Thesystemprovidesmanual/automaticmodeofthetwo,withscenecontrol,statusdisplayandalarmfailure.Inmanualmode,thefancontrolthroughtheswitchfromtheeffectsofairpressureinsidethemine.Inordertopreventfatiguefanrunning,inanystateinthecumulativefanruntimesettoswitchtoanothermachinerunningthetyphoon.AGroupBGroupcentrifugalfancentrifugalfanwithtwoswitchescanbeconverted.Timecyclesandtimingcanberandomlyset.Aresoundandlightalarmsignalform.VoiceAlarm(electricflute)buttoncanbeusedtolift,alarmtroubleshootinginstructionsautomaticallydisappear.Inautomaticmode,theuseofairpressureFarEasToneminedetectionsensorswithinthepressuresignal,thesignaltransmitterwilltransformthesiteintoaunifiedstandardsignal(eg,420mADCcurrentsignal,05VDCvoltagesignal,etc.),intotheA/Dconverteranalog-digitalconversionmodule,andthenintothePLC,PLCtodetectthepressurevaluewithsetvaluesofpressureanddealwiththeworkoftheoutputsignaltocontrolfan.Whentheairpressureinsidethemineinanatmosphericpressureorinthesettingofavalueaboveatmosphericpressure,theworkofcentrifugalfancentrifugalfanwithback-upcycleofthework；whenasuddenaccident,theminesairpressureislowerthanasetofatmosphericpressurevalue,theworkofcentrifugalfancentrifugalfanwithback-upcycleisnolongerwork,andautomaticallyswitchtotheworkatthesametime,increasethevolumeofthemineventilation,mineuntilthepressurerosetovaluessetaboveatmosphericpressure,theworkofventilationcentrifugalfanwithback-upmachinetoresumethecycleofwork3.Gasinthemineforwindsystems,coalminegasconcentrationinthegasconcentrationdetectionsensorwithatransmittersignalwillbethesitetransformintoaunifiedstandardsignal,intotheA/Dconverteranalog-digitalconversionmodule,andthenintothePLC,thesamewillbedetectedbythePLCandsetnumericalvaluesforcomparison,whenthegasconcentrationgreaterthanthevalueaftertheset,PLCoutputsignalstocontrolfantostopworking,andtheoutputsignalpowerwasautomaticallycutminetomeettherequirementsofwindpowerinterlocktoavoidelectronicsparkslitthegastopreventgasexplosionaccident.系統(tǒng)的設(shè)計(jì)功能本控制系統(tǒng)具有離心通風(fēng)機(jī)組的啟動(dòng)、互鎖和過(guò)熱保護(hù)等功能。與常規(guī)繼電器實(shí)施的通風(fēng)系統(tǒng)相比，PLC系統(tǒng)具有故障率低、可靠性高、接線簡(jiǎn)單、維護(hù)方便等諸多優(yōu)點(diǎn)，PLC的控制功能使通風(fēng)系統(tǒng)的自動(dòng)化程度大大提高，減輕了崗位人員的勞動(dòng)強(qiáng)度。PLC和變頻器與空氣壓力變送器配合使用，使系統(tǒng)控制的安全性、可靠性大大提高，也使通風(fēng)機(jī)運(yùn)行的故障率大大降低，不僅節(jié)約了電能，而且還提高了設(shè)備的運(yùn)轉(zhuǎn)率。為滿足礦井通風(fēng)系統(tǒng)自動(dòng)控制的要求，系統(tǒng)的具體設(shè)計(jì)要求如下：（1）本系統(tǒng)提供手動(dòng)自動(dòng)兩種工作模式，具有狀態(tài)顯示以及故障報(bào)警等功能。（2）模擬量壓力輸入經(jīng)PID運(yùn)算，輸出模擬量控制變頻器。（3）在自動(dòng)方式下，當(dāng)井下壓力低于設(shè)定壓力下限時(shí)，兩組風(fēng)機(jī)將同時(shí)投入工作運(yùn)行，同時(shí)并發(fā)出指示和報(bào)警信號(hào)。（4）模擬量瓦斯輸入，當(dāng)?shù)V井瓦斯?jié)舛却笥谠O(shè)定報(bào)警上限時(shí)，發(fā)出指示和報(bào)警。當(dāng)瓦斯?jié)舛却笥谠O(shè)定斷電上限時(shí)，PLC將切斷工作面和風(fēng)機(jī)組電源，防止瓦斯爆炸。（5）運(yùn)用溫度傳感器測(cè)定風(fēng)機(jī)組定子溫度或軸承溫度，當(dāng)定子溫度或軸承溫度超過(guò)設(shè)定報(bào)警上線時(shí)，發(fā)出指示和報(bào)警信號(hào)。當(dāng)定子溫度或軸承溫度超過(guò)設(shè)定風(fēng)機(jī)組轉(zhuǎn)換溫度界線時(shí)，PLC將切斷指示和報(bào)警信號(hào)并自動(dòng)切斷當(dāng)前運(yùn)行風(fēng)機(jī)組，在自動(dòng)方式下并能自動(dòng)接入另一臺(tái)風(fēng)機(jī)組運(yùn)行，若在手動(dòng)方式下，工作人員手動(dòng)切換1。（6）為防止離心風(fēng)機(jī)的