有功功率和無功功率

有功功率/無功功率A,Activepower/reactivepower在交流電路中，由電源供給負載的電功率有兩種；一種是有功功率，一種是無功功率。有功功率是保持用電設(shè)備正常運行所需的電功率，也就是將電能轉(zhuǎn)換為其他形式能量(機械能、光能、熱能)的電功率。比如：5.5千瓦的電動機就是把5.5千瓦的電能轉(zhuǎn)換為機械能，帶動水泵抽水或脫粒機脫粒；各種照明設(shè)備將電能轉(zhuǎn)換為光能，供人們生活和工作照明。有功功率的符號用P表示，單位有瓦(W)、千瓦(kW)、兆瓦(MW)。無功功率比較抽象，它是用于電路內(nèi)電場與磁場的交換，并用來在電氣設(shè)備中建立和維持磁場的電功率。它不對外作功，而是轉(zhuǎn)變?yōu)槠渌问降哪芰?。凡是有電磁線圈的電氣設(shè)備，要建立磁場，就要消耗無功功率。比如40瓦的日光燈，除需40多瓦有功功率(鎮(zhèn)流器也需消耗一部分有功功率)來發(fā)光外，還需80乏左右的無功功率供鎮(zhèn)流器的線圈建立交變磁場用。由于它不對外做功，才被稱之為“無功”。無功功率的符號用Q表示，單位為乏(7狗或千乏(kVar)。無功功率決不是無用功率，它的用處很大。電動機需要建立和維持旋轉(zhuǎn)磁場，使轉(zhuǎn)子轉(zhuǎn)動，從而帶動機械運動，電動機的轉(zhuǎn)子磁場就是靠從電源取得無功功率建立的。變壓器也同樣需要無功功率，才能使變壓器的一次線圈產(chǎn)生磁場，在二次線圈感應出電壓。因此，沒有無功功率，電動機就不會轉(zhuǎn)動，變壓器也不能變壓，交流接觸器不會吸合。為了形象地說明這個問題，現(xiàn)舉一個例子：農(nóng)村修水利需要開挖土方運土，運土時用竹筐裝滿土，挑走的土好比是有功功率，挑空竹筐就好比是無功功率，竹筐并不是沒用，沒有竹筐泥土怎么運到堤上呢？在正常情況下，用電設(shè)備不但要從電源取得有功功率，同時還需要從電源取得無功功率。如果電網(wǎng)中的無功功率供不應求，用電設(shè)備就沒有足夠的無功功率來建立正常的電磁場，那么，這些用電設(shè)備就不能維持在額定情況下工作，用電設(shè)備的端電壓就要下降，從而影響用電設(shè)備的正常運彳亍。無功功率對供、用電產(chǎn)生一定的不良影響，主要表現(xiàn)在：降低發(fā)電機有功功率的輸出。降低輸、變電設(shè)備的供電能力。造成線路電壓損失增大和電能損耗的增加。（4）造成低功率因數(shù)運行和電壓下降，使電氣設(shè)備容量得不到充分發(fā).1。從發(fā)電機和高壓輸電線供給的無功功率，遠遠滿足不了負荷的需要，所以在電網(wǎng)中要設(shè)置一些無功補償裝置來補充無功功率，以保證用戶對無功功率的需要，這樣用電設(shè)備才能在額定電壓下工作。這就是電網(wǎng)需要裝設(shè)無功補償裝置的道理。電壓電流同相位，電源向負載供電，負載把電能轉(zhuǎn)換成其他能量，叫有功。電壓電流不同相位部分，電源與負載之間交換電能，這部分（除線路損耗外）電能不轉(zhuǎn)換（電磁以外的）成其他能量，叫無功。有功功率有功功率是保持用電設(shè)備正常運行所需的電功率，也就是將電能轉(zhuǎn)換為其他形式能量（機械能、光能、熱能）的電功率。比如：5.5千瓦的電動機就是把5.5千瓦的電能轉(zhuǎn)換為機械能，帶動水泵抽水或脫粒機脫粒；各種照明設(shè)備將電能轉(zhuǎn)換為光能，供人們生活和工作照明。有功功率的符號用P表示，單位有瓦（W）、千瓦（kW）、兆瓦（MW）。定義：有功功率:在交流電路中，電源在一個周期內(nèi)發(fā)出瞬時功率的平均值（或負載電阻所消耗的功率），稱為"有功功率”。有功功率過低導致線損增加、容量下降、設(shè)備使用率下降，從而導致電能浪費加大。無功功率電網(wǎng)中的感性負載（如電機，扼流圈，變壓器，感應式加熱器及電焊機等）都會產(chǎn)生不同程度的電滯，即所謂的電感。感性負載具有這樣一種特性-----即使所加電壓改變方向，感性負載的這種滯后仍能將電流的方向（如正向）保持一段時間。一旦存在了這種電流與電壓之間的相位差，就會產(chǎn)生負功率，并被反饋到電網(wǎng)中。電流電壓再次相位相同時，又需要相同大小的電能在感性負載中建立磁場，這種磁場反向電能就被稱作無功功率。定義：在具有電感或電容的電路中，在每半個周期內(nèi)，把電源能量變成磁場（或電場）能量貯存起來，然后，再釋放，又把貯存的磁場（或電場）能量再返回給電源，只是進行這種能量的交換，并沒有真正消耗能量，我們把這個交換的功率值，稱為”無功功率”。無功功率比較抽象，它是用于電路內(nèi)電場與磁場的交換，并用來在電氣設(shè)備中建立和維持磁場的電功率。它不對外作功，而是轉(zhuǎn)變?yōu)槠渌问降哪芰?。凡是有電磁線圈的電氣設(shè)備，要建立磁場，就要消耗無功功率。比如40瓦的日光燈，除需40多瓦有功功率(鎮(zhèn)流器也需消耗一部分有功功率)來發(fā)光外，還需80乏左右的無功功率供鎮(zhèn)流器的線圈建立交變磁場用。由于它不對外做功，才被稱之為“無功”。無功功率的符號用Q表示，單位為乏(Var)或千乏(kVar)。無功功率過高的缺點：無功功率會導致電流增大和視在功率增加，導致系統(tǒng)容量下降；無功功率增加，會使總電流增加，從而使設(shè)備和線路的損耗增加；使線路的壓降增大，沖擊性無功負載還會使電壓劇烈波動。配電網(wǎng)中的電感性電氣設(shè)備如變壓器、電動機、電焊機、空調(diào)器、洗衣機、電冰箱、鈉燈、日光燈等投入運行后，不僅要從電力網(wǎng)中吸收有功功率用于做功，而且還要吸收無功功率建立磁場，這樣就導致電力客戶的自然功率因數(shù)一般都比較低。我國對電力客戶的用電，規(guī)定了必須達到的功率因數(shù)標準。有功可以直接測量；有功與無功混在一起，無法直接區(qū)分開來，可以通過功率因數(shù)表測量。Inthecircuit,thepowersupplybythetwokindsofpowerload;Oneistheactivepower,onekindisreactivepower.Activepoweristomaintainthenormaloperationofthepowerequipmentneededtopower,isalsotoelectricenergyintootherformsofenergy(mechanicalenergy,lightandheatenergy)ofpower.Forexample:5.5kwmotoristhatofthe5.5kwelectricalenergyintomechanicalenergy,drivethepumpspumpingorthethreshersthreshing;Lightingequipmentwillbeelectricenergyintolightenergyconversion,forpeoplelivingandworkinglighting.ThesymboloftheactivepowerwithPsays,theunithaswatts(w),kilowatts(kW),megawatts(MW).Reactivepowerareabstract,itwasusedinthecircuitofelectricandmagneticfieldexchange,andusedinelectricalequipmenttoestablishandmaintainthemagneticfieldofpower.Itisnotforeignenergy,butchangedintootherformsofenergy.Anyonewithamagneticcoilofelectricalequipment,tobuildamagneticfield,areabouttouseupreactivepower.Suchas40wattsoffluorescentlamp,inadditiontomorethan40tileactivepower(ballastalsoneedtoconsumepartofactivepower)toshineoutside,stillneedtobearound80lackofreactivepowerforballastcoilsetupwithalternatingmagneticfield.Becauseitisnotforeignwork,tobecalled"reactivepower".Reactivepowersymbolusingqqsaid,theunitisdeficient(Var)orlackofthousands(kVar).Reactivepowerisnotuselesspower,it'sveryuseful.Motorneedtoestablishandmaintainarotatingmagneticfield,maketherotor,thuspromotemechanicalmotion,motorrotormagneticfieldisobtainedfrompowerbyreactivepowerbuilt.Transformeralsorequirethereactivepower,cancausethetransformeracoilproduceamagneticfield,attwotimesthevoltageinductioncoil.Therefore,noreactivepower,themotordoesnotturn,transformercannotvariablepressure,accontactorwon'tsuck$.Inordertotheimageoftheillustrationofthisproblem,wegiveanexample:ruralwaterneedtorepaircarriedearthexcavationearthwork,carriedearthwithZhuKuangwhenfilledwithearth,theearthislikepickisactivepower,ZhuKuangcarryemptyislikeareactivepower,ZhuKuangandnotauseless,noZhuKuangclaytoDiShanghow?Innormalcircumstances,electricalequipmentfrompowernotonlytogetactivepower,whichneedstobeobtainedfromthepowersupplyreactivepower.Ifinthegridreactivepowerdemandexceedssupply,powerequipmentisnotenoughreactivepowertoestablishnormalelectromagneticfields,so,theelectricequipmentcannotbemaintainedintheratedwork,electricalequipmentwilldeclinevoltage,whichaffectsthenormaloperationofthepowerequipment.Reactivepowerforelectricitytoproduceacertain,badinfluence,mainlydisplaysin:reducetheoutputoftheactivepowergenerator.reducethelossofpowersupply,thesubstationequipment.causelinevoltagelossincreaseandtheincreaseoftheelectricpower.causelowpowerfactoroperationandvoltagefell,theelectricalequipmentcapacitycannotmakefullplay.Fromthegeneratorandthehighvoltagetransmissionlineofreactivepowersupply,farmeettheneedsoftheload,sointhepowergridtosetsomeofthereactivepowercompensationdevicetosupplementthereactivepower,inordertoensurethattheusertothereactivepowerneeded,sothatpowerequipmentcanworkunderratedvoltage.Thisisthepowergridneedsreactivepowercompensationdevicesofreason.Voltagecurrentwithphase,thepowertoloadpowersupply,theloadtheenergyconversiontootherenergy,calledactive.Voltagecurrentdifferentphasepart,sourceandloadexchangebetweenpower,thispart(exceptthelinelossoutside)powernottoconvert(electromagneticoutsideofthe)intootherenergy,calledreactive.ActivepowerActivepoweristomaintainthenormaloperationofthepowerequipmentneededtopower,isalsotoelectricenergyintootherformsofenergy(mechanicalenergy,lightandheatenergy)ofpower.Forexample:5.5kwmotoristhatofthe5.5kwelectricalenergyintomechanicalenergy,drivethepumpspumpingorthethreshersthreshing;Lightingequipmentwillbeelectricenergyintolightenergyconversion,forpeoplelivingandworkinglighting.ThesymboloftheactivepowerwithPsays,theunithaswatts(w),kilowatts(kW),megawatts(MW).Definition:activepower:inthecircuit,thepowersupplyinacycleofinsideaninstantaneouspoweraverage(orloadresistanceofpowerconsumption),knownasthe"activepower".Activepoweristoolowtoincreasecapacitydrops,andlineloss,equipmentutilizationrateisreduced,whichcanleadtoincreasedpowerwaste.ReactivepowerInthegridperceptualload(suchasmotor,choke,transformer,inductionheaterandelectric)producedifferentdegreeofelectricitysluggish,theso-calledinductance.Theperceptualloadhassuchacharacteristics-evenifthevoltagechangeofdirection,perceptualloadthislagstillcurrentdirection(suchaspositive)keepaperiodoftime.Onceexistedforthiscurrentandvoltageofthephasedifferencebetween,canproducenegativepower,andinthepowertobefeedback.Againthesameincurrentvoltagephase,andtheneedtosamesizeoftheelectricityintheperceptualloadestablishedinmagneticfield,themagneticfieldreversepowerisknownasreactivepower.Definition:inainductororcapacitancecircuit,ineachhalfacycle,thepowerenergyintothemagneticfield(orelectricfield)energystored,andthen,thenreleased,andthestorageofthemagneticfield(orelectricfield)energyreturnedtopoweragain,justthisenergyexchange,andnorealenergyconsumption,andweputtheexchangevalueofpower,called"reactivepower".Reactivepowerareabstract,itwasusedinthecircuitofelectricandmagneticfieldexchange,andusedinelectricalequipmenttoestablishandmaintainthemagneticfieldofpower.Itisnotforeignenergy,butchangedintootherformsofenergy.Anyonewithamagneticcoilofelectricalequipment,tobuildamagneticfield,areabouttouseupreactivepower.Suchas40wattsoffluorescentlamp,inadditiontomorethan40tileactivepower(ballastalsoneedtoconsumepartofactivepower)toshineoutside,stillneedtobearound80lackofreactivepowerforballastcoilsetupwithalternatingmagneticfield.Becauseitisnotforeignwork,tobecalled"reactivepower".Reactivepowersymbolusingqqsaid,theunitisdeficient(Var)orlackofthousands(kVar).Reactivepowertheshortcomingsofhigh1)reactivepowerwillleadtocurrentincreasesandinstalledpowerincrease,causethesystemcapacitydrops;2)reactivepowerincrease,canmakethetotalcurrentincrease,whichmakesequipmentandlinelossincrease;3)makelinepressuredropincreases,impactreactiveloadwillalsomakevoltagesharpfluctuations.Thedistributionnetworkinductiveelectricalequipmentsuchastransformer,electricmotors,electricweldingmachine,airconditioner,washingmachines,refrigerators,sodiumlamp,fluorescentlamp,andotherinputsaftertheoperation,notonlytoabsorbtheactivepowerfromthegridforwork,butalsotoabsorbreactivepowerestablishmagneticfield,thisleadstoelectricpowercustomerthenaturalpowerfactoriscomparedcommonlylow.Ourcountrytoelectricpowercustomertheelectricity,provisionsmustbemetthepowerfactorofstandards.Activecanbedirectlymeasured;Activeandreactivemixtogether,notdirectlytodistinguish,t什么叫功率因數(shù)？在電路由感性或讓性能源存儲設(shè)備，電壓和電流有相位差，流行講就是電壓和電流不相同的時間；因此，表面看電壓、電流大小如何，實際的和沒有做那么大的工作，有權(quán)力和能源存儲設(shè)備的能源轉(zhuǎn)換;所謂的裝機功率。目前，電力有源+無功功率。的意思是,無論有功功率和無功功率是多少,只能輸出電壓和電流太大。是有功功率和無功功率適量，因為有功功率和無功功率成90度角,用鐵鉤電力變壓器容量安裝power稱,單位是current-voltage(VA)。功率因數(shù)計算公式。有功功率與視在功率之比如果你家里的“感性負載的“更重要的是，如汽車、微波爐……用電器，比如更，吸收的反應將會更多,和功率因數(shù)小，電力部門是小(無功功率不消費，只是從電網(wǎng)到你的家庭電器在吸收)對于企業(yè),供電部門有監(jiān)管權(quán)力的數(shù)值，高于彩票，下面的懲罰。哈哈。相當復雜，其中涉及到安全的電力，電壓……當然，包括變電站設(shè)備投資和投入運行的可靠性、安全性和成本。而電力可以訪問為測量。Whatiscalledpowerfactor?Inthecircuit,thevoltage</view/10954.htm>andthephasedifferencebetweenthecurrent(e)calledthecosinepowerfactor,withsymbolscosesaid,innumerical,powerfactorisactivepowerandinstalledpower</view/56022.htm>ratio,namelycose=P/SWhatisinstalledpower?Inthecircuit,withperceptualorletsexualenergystorageequipment,thevoltageandcurrentwithaphasedifference,popularspeakbevoltageandcurrentisnotthesametime;Therefore,thesurfaceseevoltageis,howcurrentsize,actualanddidn'tdosobigofwork,therearepowerandenergystorageequipmentenergyconversion;Socalledinstalledpower.Already,theactivepower+reactivepower.Mean,whatevertheactivepowerandthereactivepowerishowmuch,canonlyoutputvoltageandcurrentsobig.Istheactivepowerandthereactivepowerandrightamount,becausetheactivepowerandthereactivepowerintoa90degreeAngle,withhookpowertransformerinstalledwithpowersaidcapacity,theunitiscurrent-voltage(VA).Stockscancalculatetheorem.Activepower/installedpower=powerfactor,Ifyourhome"perceptualload"ismore,suchasmotor,microwaveoven...Withelectricequipmentsuchasmore,theabsorptionofreactivewillmore,andpowerfactorissmall,theelectricitypowerdepartmentislittle(reactivepowerisnotconsume,justfromthepowergridtoyourhomeelectricalappliancesintheabsorption)Regardingtheenterprise,powersupplydepartmentshavetheregulationofpowerfornumericalvalues,higherthanthelottery,belowtothepunishment.Haha.Quitecomplicated,whichrelatestosafetyofpower,voltage...And,ofcourse,involvesthetransformersubstationequipmentinvestmentandputintooperationreliability,safetyandcost.hroughpowercanaccessformeasurement.什么叫視在功率？在交流電路中，由于有感性或容性儲能設(shè)備，電壓與電流有相位差，通俗講就是電壓與電流不在同一時間到達；因此，表面看電壓有多大、電流有多大，實際并沒有做那么大的功，有電源與儲能設(shè)備的能量轉(zhuǎn)換；所以稱為視在功率。既，有功功率+無功功率。電力變壓器就用視在功率表示容量，單位為伏安(VA)。意思是不管有功功率與無功功率是多少，只能輸出這么大的電壓與電流。視在功率:在具有阻抗的交流電路中，電壓有效值與電流有效值的乘積值，稱為"視在功率"，它不是實際做功的平均值，也不是交換能量的最大速率，只是在電機或電氣設(shè)備設(shè)計計算較簡便的方法。關(guān)系:視在功率的平方=有功功率的平方+無功功率的平方Whatisinstalledpower?Inthecircuit,withperceptualorletsexualenergystorageequipment,thevoltageandcurrentwithaphasedifference,popularspeakb