清华考研 电路原理课件 第13章 三相电路

清华大学电路原理电子课件江辑光版参考教材：《电路原理》（第2版）清华大学出版社，2007年3月江辑光刘秀成《电路原理》清华大学出版社，2007年3月于歆杰朱桂萍陆文娟《电路》（第5版）高等教育出版社，2006年5月邱关源罗先觉第第第第13131313章章章章三相电路三相电路三相电路三相电路第第第第第第第第1313131313131313章章章章章章章章三相电路三相电路三相电路三相电路三相电路三相电路三相电路三相电路13.113.113.113.1三相电源13.113.113.113.1三相电源13.213.213.213.2对称三相电路13.213.213.213.2对称三相电路13.313.313.313.3不对称三相电路示例13.313.313.313.3不对称三相电路示例13.413.413.413.4三相电路的功率13.413.413.413.4三相电路的功率本章重点本章重点����本章重点本章重点本章重点本章重点••••对称三相电路在不同联接方式下，相电压与线电压、相电流与线电流的关系。••••对称三相电路的抽单相计算方法。••••不对称三相电路的计算。••••三相电路功率的计算与量测。返回目录返回目录返回目录返回目录一、对称三相电源的产生转子：特殊形状的电磁铁（BBBB正弦分布）三相同步发电机示意图13.113.1三相电源（三相电源（Three-PhaseSourcesThree-PhaseSources））定子：完全相同三个绕组在空间互差120120120120oooo设：AAAA、BBBB、CCCC为始端,X,X,X,X、YYYY、ZZZZ为末端SSSSNNNNººººººººIIIIωωωωAAAAZZZZBBBBXXXXCCCCYYYYtttt1.1.1.1.对称三相电源的产生当转子以角速度ωωωω转动时，三个线圈中便产生感应电动势。AAAAXXXXBBBBYYYYCCCCZZZZeeeeAAAAeeeeBBBBeeeeCCCC���120120120120120120120120120120120120AAAACCCCCCCCBBBBBBBBAAAAeeeeeeeeeeeeeeeeeeeeeeee领先领先领先mmmmUUUUωωωω⎧⎧⎧⎧⎪⎪⎪⎪⎨⎨⎨⎨⎪⎪⎪⎪⎩⎩⎩⎩相同相同相位不同三个线圈中感应电动势特点::::AAAA++++––––XXXXuuuuAAAABBBB++++––––YYYYuuuuBBBBCCCC++++––––ZZZZuuuuCCCC���120120120120120120120120120120120120AAAACCCCCCCCBBBBBBBBAAAAuuuuuuuuuuuuuuuuuuuuuuuu领先领先领先三相电源符号a.a.a.a.瞬时值表达式AAAA++++––––XXXXuuuuAAAABBBB++++––––YYYYuuuuBBBBCCCC++++––––ZZZZuuuuCCCCb.b.b.b.波形图ωωωωtttt0000uuuuAAAAuuuuBBBBuuuuuuuuCCCC))))120120120120sin(sin(sin(sin(2222))))(((())))120120120120sin(sin(sin(sin(2222))))((((sinsinsinsin2222))))((((ooooCCCCooooBBBBAAAA++++====−−−−========ttttUUUUttttuuuuttttUUUUttttuuuuttttUUUUttttuuuuωωωωωωωωωωωω2.2.2.2.对称三相电源的表示c.c.c.c.相量表示3.3.3.3.对称三相电源的特点00000000CCCCBBBBAAAACCCCBBBBAAAA====++++++++====++++++++UUUUUUUUUUUUuuuuuuuuuuuu̇̇̇ooooCCCCooooBBBBooooAAAA1201201201201201201201200000∠∠∠∠====−−−−∠∠∠∠====∠∠∠∠====UUUUUUUUUUUUUUUUUUUUUUUU̇̇̇BBBBUUUU̇120120120120°°°°120120120120°°°°120120120120°°°°CCCCUUUU̇AAAAUUUU̇正序（positivesequencepositivesequencepositivesequencepositivesequence）AAAA-BBBB-CCCC-AAAA以后如果不加说明，一般都认为是正相序。4.4.4.4.对称三相电源的相序（phasesequencephasesequencephasesequencephasesequence）：每相电源经过同一值（如最大值）的先后顺序。负序（negativesequencenegativesequencenegativesequencenegativesequence）AAAA-CCCC-BBBB-AAAAAAAABBBBCCCC电压相量图AAAACCCCBBBB电压相量图二、对称三相电源的联接三个绕组的末端XXXX，YYYY，ZZZZ接在一起，从始端AAAA，BBBB，CCCC引出线。名词介绍：②中线：XXXX，YYYY，ZZZZ连接点引出线。1.1.1.1.星形联接(Y(Y(Y(Y接))))AAAA++++––––XXXX++++––––++++––––BBBBCCCCYYYYZZZZAAAABBBBCCCCNNNNAAAAUUUU̇BBBBUUUU̇CCCCUUUU̇③线电压(linevoltage)(linevoltage)(linevoltage)(linevoltage)：火线与火线之间的电压CACACACABCBCBCBCABABABAB,,,,,,,,UUUUUUUUUUUU̇̇̇ABABABABUUUU̇BCBCBCBCUUUU̇CACACACAUUUU̇4444相电压(phasevoltage)(phasevoltage)(phasevoltage)(phasevoltage)：每相电源((((负载))))的电压CCCCBBBBAAAA,,,,,,,,UUUUUUUUUUUU̇̇̇①火线((((端线))))：AAAA，BBBB，CCCC三端引出线。YYYY接三相电源的线电压与相电压的关系，ooooCCCCCNCNCNCNooooBBBBBNBNBNBNooooAAAANNNNAAAA1201201201201201201201200000∠∠∠∠========−−−−∠∠∠∠========∠∠∠∠========UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU̇̇̇̇̇̇设BNBNBNBNNNNNAAAABBBBAAAAUUUUUUUUUUUU̇̇̇−−−−====���3030303033331201201201200000∠∠∠∠====−−−−∠∠∠∠−−−−∠∠∠∠====UUUUUUUUUUUUooooooooooooCNCNCNCNNNNNBBBBCCCCBBBB909090903333120120120120120120120120−−−−∠∠∠∠====∠∠∠∠−−−−−−−−∠∠∠∠====−−−−====UUUUUUUUUUUUUUUUUUUUUUUU̇̇̇ooooooooooooNNNNAAAACNCNCNCNCACACACA15015015015033330000120120120120∠∠∠∠====∠∠∠∠−−−−∠∠∠∠====−−−−====UUUUUUUUUUUUUUUUUUUUUUUU̇̇̇AAAA++++––––XXXX++++––––++++––––BBBBCCCCYYYYZZZZAAAABBBBCCCCNNNNCCCCUUUU̇AAAAUUUU̇BBBBUUUU̇ABABABABUUUU̇CACACACAUUUU̇BCBCBCBCUUUU̇则：利用相量图得到相电压和线电压之间的关系：线电压对称((((大小相等，相位互差120120120120oooo))))ABABABABUUUU̇30303030oooo30303030ooooCACACACAUUUU̇BCBCBCBCUUUU̇ANANANANCNCNCNCNCACACACACNCNCNCNBNBNBNBNBCBCBCBCBNBNBNBNANANANANABABABABUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU̇̇̇̇̇̇̇̇̇−−−−====−−−−====−−−−====30303030ooooooooNNNNAAAABBBBAAAA303030303333∠∠∠∠====UUUUUUUU̇̇ooooCNCNCNCNCACACACAooooNNNNBBBBCCCCBBBB303030303333303030303333∠∠∠∠====∠∠∠∠====UUUUUUUUUUUUUUUU̇̇̇̇CNCNCNCNUUUU̇ANANANANUUUU̇BNBNBNBNUUUU̇BNBNBNBNUUUU̇−−−−三个单相电源首尾相接，由三个连接点引出三条线。注意：始端末端要依次相连不能搞错。IIII=0=0=0=0，∆∆∆∆接电源中不会产生环流。0000CCCCBBBBAAAA====++++++++UUUUUUUUUUUU̇̇̇思考：会否将电源毁坏？2.2.2.2.三角形联接((((∆∆∆∆接))))AAAA++++––––XXXX++++––––++++––––BBBBCCCCYYYYZZZZAAAABBBBCCCCCCCCUUUU̇AAAAUUUU̇BBBBUUUU̇不会....若CCCC相接反时CCCCCCCCBBBBAAAA2222UUUUUUUUUUUUUUUU̇̇̇̇−−−−====−−−−++++IIII≠≠≠≠0,0,0,0,∆∆∆∆接电源中将会产生环流。思考：如何保证不接错？AAAAUUUU̇BBBBUUUU̇CCCCUUUU̇正确接法CCCC2222UUUU̇−−−−接反了CCCCUUUU̇−−−−∆∆∆∆接三相电源的线电压与相电压的关系AAAA++++––––XXXX++++––––++++––––BBBBCCCCYYYYZZZZAAAABBBBCCCCCCCCUUUU̇AAAAUUUU̇BBBBUUUU̇ooooCCCCooooBBBBooooAAAA1201201201201201201201200000∠∠∠∠====−−−−∠∠∠∠====∠∠∠∠====UUUUUUUUUUUUUUUUUUUUUUUU̇̇̇设ooooCCCCCACACACAooooBBBBBCBCBCBCooooAAAAABABABAB1201201201201201201201200000∠∠∠∠========−−−−∠∠∠∠========∠∠∠∠========UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU̇̇̇̇̇̇线电压等于对应的相电压。返回目录返回目录返回目录返回目录一、YYYY－YYYY接对称三相电路的计算13.213.2对称三相电路的计算对称三相电路的计算++++____++++________++++NNNNnnnnZZZZZZZZZZZZCCCCUUUU̇ZZZZllllZZZZllllZZZZllllZZZZNNNNBBBBUUUU̇AAAAUUUU̇CCCCIIIİBBBBIIIİAAAAIIIİ对称三相电路(symmetricalthree-phasecircuit):(symmetricalthree-phasecircuit):(symmetricalthree-phasecircuit):(symmetricalthree-phasecircuit):电源对称,负载对称,火线阻抗相等的三相电路。相电流(phasecurrent)(phasecurrent)(p