直流電路主講人牛小偉ZHENGZHOURAILWAYVOCATIONAL&TECHNICALCOLLEGE客車電氣裝置/BUSELECTRICALINSTALLATION主講人牛小偉SpeakerNiuxiaowei直流電路發(fā)電車I號(hào)機(jī)組直流報(bào)警保護(hù)電路如圖3一22所示。TheDCprotectioncircuitoftheIgeneratorcarisshowninthefollowingfigure.該電路可以實(shí)現(xiàn)過(guò)流預(yù)報(bào)警、過(guò)流脫扣報(bào)警、逆功率脫扣報(bào)警、繞組高溫報(bào)警和高水溫報(bào)警，另外還可以進(jìn)行電路的試報(bào)警及報(bào)警時(shí)的消音、報(bào)警故障處理后的復(fù)位等操作。Thiscircuitcanrealizeover-currentpre-alarm,over-currenttrippingalarm,reversepowertrippingalarm,windinghightemperaturealarm,andhighwatertemperaturealarm.Inaddition,itcanalsoperformcircuittestalarm,noisereductionduringalarm,resettingafteralarmfaulthandling,andotheroperations.發(fā)電車三臺(tái)機(jī)組的報(bào)警保護(hù)電路原理相同，其中I號(hào)機(jī)組幾個(gè)報(bào)警保護(hù)電路的工作過(guò)程分析如下:Theprincipleofthealarmprotectioncircuitofthethreeunitsofgeneratorcaristhesame.Theoperatingprocessisanalyzedasfollow:

2．發(fā)電車直流報(bào)警保護(hù)電路

TheDCalarmingprotectioncircuitofgeneratorcar.直流電路主開(kāi)關(guān)電路Mainswitchingcircuits直流電路當(dāng)I號(hào)發(fā)電機(jī)輸出線電流超過(guò)預(yù)報(bào)警電流600A時(shí)，WhentheoutputlinecurrentoftheIgeneratorcarexceedsthepre-alarmcurrent600A使141與700號(hào)線接通，繼電器1KA6得電吸合，接通報(bào)警電路中的721號(hào)線與723號(hào)線間常開(kāi)觸點(diǎn)，報(bào)警指示燈7HL1點(diǎn)亮，同時(shí)，繼電器7KA2得電吸合，電鈴電路接通，電路實(shí)現(xiàn)聲光雙報(bào)警。Thenline141andline700areconnected,andrelay1KA6ispoweredonandclosed;thenormallyopencontactbetweenline721andline723inthealarmcircuitisconnected,andthealarmindicatinglamp7HL1lightsup.Therefore,relay7KA2canbepoweredonandclosed,theelectricbellcircuitisconnected,andthecircuitrealizesbothsoundandlightalarm.1QF主開(kāi)關(guān)的17與18號(hào)端子間的微動(dòng)開(kāi)關(guān)閉合，Thesensitiveswitchbetweenterminals17and18ofthe1QFmainswitchisclosed.電鈴1KA6自鎖觸點(diǎn)相應(yīng)的電氣通路如下：Thecorrespondingelectricalpathwaysareasfollows:過(guò)流預(yù)報(bào)警Over-currentpre-alarm（1）直流電路指示燈7HLI電路（光報(bào)警）:704(+)-7FU7-733-721-1KA6（閉合）->723-7HL1線圈-7(X）。7KA2線圈電路704(+)-7FU7-733-721-1KA6（閉合）--723-7V1-732-7KA2線圈一70007KA1觸點(diǎn)斷開(kāi)，電鈴斷電直流電路電警笛（7JD1）電路Electricalarmcircuit704(+)-7FU7-733-721--7KA2（閉合closed）-731-7KA1（常閉normallyclosed）-730-7JD1700。電路中的Vol為續(xù)流二極管，它可以釋放7JD1中的線圈在通電與斷電時(shí)所產(chǎn)生的感應(yīng)電流，以防止影響其他電路的正常工作。The

freewheeling

diodeVo1inthiscircuitcanreleasetheinducedcurrentofthecoilin7JD1whichisgeneratedwhenthecoilispoweredonandoff,sothatthediodecanenablethenormaloperationsofothercircuits.消音電路Noisereductioncircuit當(dāng)出現(xiàn)報(bào)警后，按下消音按鈕7SB2,7KA1線圈得電，其常閉觸點(diǎn)斷開(kāi)，電警笛電路被切斷，電警笛停止工作。Whenanalarmoccurs,pressthenoisereductionbutton7SB2.Thenthecoil7KA1ispoweredon,itsnormallyclosedcontactisdisconnected,andtheelectricsirencircuitispoweredoff.Finally,theelectricalarmstopsworking.7KA1觸點(diǎn)斷開(kāi)，電鈴斷電直流電路主開(kāi)關(guān)1QF自動(dòng)分閘，電路實(shí)現(xiàn)脫扣功能，同時(shí)主開(kāi)關(guān)上的21與22接線端間微動(dòng)開(kāi)關(guān)閉合，140與700號(hào)線接通（見(jiàn)圖3一14)，繼電器1KA7得電吸合，接通報(bào)警電路中的721號(hào)線與724號(hào)線間常開(kāi)觸點(diǎn)，報(bào)警指示燈7HL2及報(bào)警動(dòng)作繼電器7KA2得電，電路實(shí)現(xiàn)聲光雙報(bào)警。Themainswitch1QFisautomaticallyopened,andthecircuitrealizesthetrippingfunction.Meanwhile,thesensitiveswitchbetweentheterminals21and22onthemainswitchisclosed,thelines140and700areconnected(seeFigure3-14),therelay1KA7ispoweredonandclosed.Thenthenormallyopencontactbetweenline721andline724inthealarmcircuitisconnectedandthealarmindicatinglamp7HL2andthealarmrelay7KA2arepoweredon,sothecircuitrealizesbothsoundandlightalarm.當(dāng)I號(hào)發(fā)電機(jī)輸出線電流超過(guò)脫扣（分閘）電流2000A時(shí)，WhentheoutputlinecurrentoftheIgeneratorexceedsthetripping(opening)currentof2000A,過(guò)流脫扣報(bào)警Over-currenttrippingalarm（2）直流電路如果不及時(shí)分閘，將會(huì)使發(fā)電機(jī)繞組燒損，引起嚴(yán)重后果。Ifthebrakesarenotopenedintime,thegeneratorwindingswillbeburned,causingseriousconsequences.當(dāng)發(fā)電機(jī)輸出干線上出現(xiàn)大于10％的逆功率時(shí)Whenthereisareversepowermorethan10%ontheoutputmainlineofthegenerator.1KR線圈將動(dòng)作，142與700號(hào)線接通，繼電器1KA5得電吸合，195與186線間1KA5的常開(kāi)觸點(diǎn)閉合，主開(kāi)關(guān)的分閘電路被接通而實(shí)現(xiàn)自動(dòng)分閘（見(jiàn)圖3一14)，同時(shí)721與725號(hào)線間常開(kāi)觸點(diǎn)接通，電路實(shí)現(xiàn)聲光雙報(bào)警。The1KRcoilwilloperate,theline142andline700willbeconnected,andtherelay1KA5willbepoweredonandclosed.Meanwhile,thenormallyopencontactof1KA5betweenlines195and186isclosed,theopeningcircuitofthemainswitchisconnectedtorealizeautomaticopening(seeFigure3-14),andthenormallyopencontactbetweenline721andline725isconnected.Thenthecircuitcanrealizesoundandlightalarm.逆功率脫扣報(bào)警Reversepowertrippingalarm（3）當(dāng)雙機(jī)并車或因其他原因造成I號(hào)機(jī)組功率倒灌（逆功率：一般而言，發(fā)電機(jī)的功率方向應(yīng)該為由發(fā)電機(jī)流向母線，但是當(dāng)發(fā)電機(jī)失磁或其他某種原因，發(fā)電機(jī)有可能變?yōu)殡妱?dòng)機(jī)運(yùn)行，即從系統(tǒng)中吸取有功功率。這就是逆功率。）時(shí)，

WhenthetwogeneratorsoperateinparallelorthepowerofunitIisreversed(onreversepower)causedbyotherreasons.直流電路繞組高溫報(bào)警后應(yīng)立即減載或停止供電，待查明原因并作相應(yīng)處理后才可恢復(fù)正常供電。Afterthewindinghightemperaturealarm,theloadshouldbereducedorthepowersupplyshouldbecutoffimmediately.Whenthecauseisfoundoutandthecorrespondingtreatmentistaken,thepowersupplycanberestored.當(dāng)發(fā)電機(jī)電樞繞組內(nèi)部由于某種原因溫度過(guò)高（超過(guò)155℃）時(shí)，繞組高溫繼電器1ZWJ動(dòng)作，721號(hào)線與726號(hào)線間觸點(diǎn)接通，報(bào)警電路發(fā)出聲光報(bào)警。Whentheinternaltemperatureofthegeneratorarmaturewindingistoohigh(exceeding155℃)forsomereason,thewindinghigh-temperaturerelay1ZWJoperates,andthecontactbetweenline721andline726isconnectedandthealarmcircuitemitsanaudibleandvisualalarm.繞組高溫報(bào)警Windinghightemperaturealarm（4）當(dāng)柴油機(jī)的水溫超過(guò)90℃時(shí)，繼電器IKA3得電吸合，報(bào)警電路中的721號(hào)線與727號(hào)線接通，電路實(shí)現(xiàn)聲光雙報(bào)警。Whenthewatertemperatureofthedieselengineexceeds90°C,therelayIKA3ispoweredonandclosed,andtheline721andline727inthealarmcircuitareconnected.Thenthecircuitcanreal