直流电路BUSELECTRICALINSTALLATION课件讲解

直流电路主讲人牛小伟ZHENGZHOURAILWAYVOCATIONAL&TECHNICALCOLLEGE客车电气装置/BUSELECTRICALINSTALLATION主讲人牛小伟SpeakerNiuxiaowei直流电路发电车I号机组直流报警保护电路如图3一22所示。TheDCprotectioncircuitoftheIgeneratorcarisshowninthefollowingfigure.该电路可以实现过流预报警、过流脱扣报警、逆功率脱扣报警、绕组高温报警和高水温报警，另外还可以进行电路的试报警及报警时的消音、报警故障处理后的复位等操作。Thiscircuitcanrealizeover-currentpre-alarm,over-currenttrippingalarm,reversepowertrippingalarm,windinghightemperaturealarm,andhighwatertemperaturealarm.Inaddition,itcanalsoperformcircuittestalarm,noisereductionduringalarm,resettingafteralarmfaulthandling,andotheroperations.发电车三台机组的报警保护电路原理相同，其中I号机组几个报警保护电路的工作过程分析如下:Theprincipleofthealarmprotectioncircuitofthethreeunitsofgeneratorcaristhesame.Theoperatingprocessisanalyzedasfollow:

2．发电车直流报警保护电路

TheDCalarmingprotectioncircuitofgeneratorcar.直流电路主开关电路Mainswitchingcircuits直流电路当I号发电机输出线电流超过预报警电流600A时，WhentheoutputlinecurrentoftheIgeneratorcarexceedsthepre-alarmcurrent600A使141与700号线接通，继电器1KA6得电吸合，接通报警电路中的721号线与723号线间常开触点，报警指示灯7HL1点亮，同时，继电器7KA2得电吸合，电铃电路接通，电路实现声光双报警。Thenline141andline700areconnected,andrelay1KA6ispoweredonandclosed;thenormallyopencontactbetweenline721andline723inthealarmcircuitisconnected,andthealarmindicatinglamp7HL1lightsup.Therefore,relay7KA2canbepoweredonandclosed,theelectricbellcircuitisconnected,andthecircuitrealizesbothsoundandlightalarm.1QF主开关的17与18号端子间的微动开关闭合，Thesensitiveswitchbetweenterminals17and18ofthe1QFmainswitchisclosed.电铃1KA6自锁触点相应的电气通路如下：Thecorrespondingelectricalpathwaysareasfollows:过流预报警Over-currentpre-alarm（1）直流电路指示灯7HLI电路（光报警）:704(+)-7FU7-733-721-1KA6（闭合）->723-7HL1线圈-7(X）。7KA2线圈电路704(+)-7FU7-733-721-1KA6（闭合）--723-7V1-732-7KA2线圈一70007KA1触点断开，电铃断电直流电路电警笛（7JD1）电路Electricalarmcircuit704(+)-7FU7-733-721--7KA2（闭合closed）-731-7KA1（常闭normallyclosed）-730-7JD1700。电路中的Vol为续流二极管，它可以释放7JD1中的线圈在通电与断电时所产生的感应电流，以防止影响其他电路的正常工作。The

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diodeVo1inthiscircuitcanreleasetheinducedcurrentofthecoilin7JD1whichisgeneratedwhenthecoilispoweredonandoff,sothatthediodecanenablethenormaloperationsofothercircuits.消音电路Noisereductioncircuit当出现报警后，按下消音按钮7SB2,7KA1线圈得电，其常闭触点断开，电警笛电路被切断，电警笛停止工作。Whenanalarmoccurs,pressthenoisereductionbutton7SB2.Thenthecoil7KA1ispoweredon,itsnormallyclosedcontactisdisconnected,andtheelectricsirencircuitispoweredoff.Finally,theelectricalarmstopsworking.7KA1触点断开，电铃断电直流电路主开关1QF自动分闸，电路实现脱扣功能，同时主开关上的21与22接线端间微动开关闭合，140与700号线接通（见图3一14)，继电器1KA7得电吸合，接通报警电路中的721号线与724号线间常开触点，报警指示灯7HL2及报警动作继电器7KA2得电，电路实现声光双报警。Themainswitch1QFisautomaticallyopened,andthecircuitrealizesthetrippingfunction.Meanwhile,thesensitiveswitchbetweentheterminals21and22onthemainswitchisclosed,thelines140and700areconnected(seeFigure3-14),therelay1KA7ispoweredonandclosed.Thenthenormallyopencontactbetweenline721andline724inthealarmcircuitisconnectedandthealarmindicatinglamp7HL2andthealarmrelay7KA2arepoweredon,sothecircuitrealizesbothsoundandlightalarm.当I号发电机输出线电流超过脱扣（分闸）电流2000A时，WhentheoutputlinecurrentoftheIgeneratorexceedsthetripping(opening)currentof2000A,过流脱扣报警Over-currenttrippingalarm（2）直流电路如果不及时分闸，将会使发电机绕组烧损，引起严重后果。Ifthebrakesarenotopenedintime,thegeneratorwindingswillbeburned,causingseriousconsequences.当发电机输出干线上出现大于10％的逆功率时Whenthereisareversepowermorethan10%ontheoutputmainlineofthegenerator.1KR线圈将动作，142与700号线接通，继电器1KA5得电吸合，195与186线间1KA5的常开触点闭合，主开关的分闸电路被接通而实现自动分闸（见图3一14)，同时721与725号线间常开触点接通，电路实现声光双报警。The1KRcoilwilloperate,theline142andline700willbeconnected,andtherelay1KA5willbepoweredonandclosed.Meanwhile,thenormallyopencontactof1KA5betweenlines195and186isclosed,theopeningcircuitofthemainswitchisconnectedtorealizeautomaticopening(seeFigure3-14),andthenormallyopencontactbetweenline721andline725isconnected.Thenthecircuitcanrealizesoundandlightalarm.逆功率脱扣报警Reversepowertrippingalarm（3）当双机并车或因其他原因造成I号机组功率倒灌（逆功率：一般而言，发电机的功率方向应该为由发电机流向母线，但是当发电机失磁或其他某种原因，发电机有可能变为电动机运行，即从系统中吸取有功功率。这就是逆功率。）时，

WhenthetwogeneratorsoperateinparallelorthepowerofunitIisreversed(onreversepower)causedbyotherreasons.直流电路绕组高温报警后应立即减载或停止供电，待查明原因并作相应处理后才可恢复正常供电。Afterthewindinghightemperaturealarm,theloadshouldbereducedorthepowersupplyshouldbecutoffimmediately.Whenthecauseisfoundoutandthecorrespondingtreatmentistaken,thepowersupplycanberestored.当发电机电枢绕组内部由于某种原因温度过高（超过155℃）时，绕组高温继电器1ZWJ动作，721号线与726号线间触点接通，报警电路发出声光报警。Whentheinternaltemperatureofthegeneratorarmaturewindingistoohigh(exceeding155℃)forsomereason,thewindinghigh-temperaturerelay1ZWJoperates,andthecontactbetweenline721andline726isconnectedandthealarmcircuitemitsanaudibleandvisualalarm.绕组高温报警Windinghightemperaturealarm（4）当柴油机的水温超过90℃时，继电器IKA3得电吸合，报警电路中的721号线与727号线接通，电路实现声光双报警。Whenthewatertemperatureofthedieselengineexceeds90°C,therelayIKA3ispoweredonandclosed,andtheline721andline727inthealarmcircuitareconnected.Thenthecircuitcanreal