文档介绍：第9章正弦稳态电路的分析电压三角形RU?U?CLUU???Z?RZCL??1?阻抗三角形Z?RLC串联交流电路RLC并联交流电路GYLC??1?导纳三角形Y?电流三角形I?LCII???Y?RI?第9章正弦稳态电路的分析两串联阻抗的分压公式UZZZUUZZZU????21222111????21UUU??一般情况下:21ZIZIZI??21ZZZ????????????????????ZRXXRjXRXXjRRjXRjXRZZZarctan)()()()(222121221121若两阻抗串联:第9章正弦稳态电路的分析111121111ZZZZZZZeq????IZZZIYYIeq???21211???IZZZIYYIeq???21122???21III??一般情况下:21ZUZUZU??21111ZZZ??两阻抗的并联第9章正弦稳态电路的分析§-3Vcos(5000t)2100?u,F5,12mH,15?????CLR求电流i和各元件电压相量。解设电压为参考相量:V01000??U????????eqZUI??R+-RU?+-+-CU?LU?U?I?Lj?Cj?1+-各元件电压相量U?RU?I??LU???RU?I??LU???0U?0RU?LU?CU?U?I?0CLRUUUU???????CRLUUUU???????)415(00????????IRUR??)()460(000???????ILjUL???)()440(1000??????????ICjUC???第9章正弦稳态电路的分析例9-4cos(314t)V2100?Su,F10,,1,1021???????CLkRR求各支路电流和电压。解设电压为参考相量:V01000??SU?+-RU?+-+-10U?LU?SU?I?Lj?Cj?1+-1R2R1I?2I?1010U???I?????IZU?????CZUI??????RZUI??SU?0I????2I?21III?????LRSUUUU?????????????IRUR??)()()(?????????????ILjIZULL????RU??0+1I?1I?2I?10U?RU?LU?SU?第9章正弦稳态电路的分析§?可应用在直流电路中的分析方法来分析计算复杂交流电路;?所应用的电路公式使用其相应的相量式;?电压、电动势和电流以相量表示,电阻、电容和电感以阻抗或导纳表示;?阻抗Z是复数,不是相量;注意阻抗,阻抗模与阻抗幅角的计算。复杂交流电路的分析计算要点:第9章正弦稳态电路的分析3311231321)(SSnnUYUYUYUYYY?????????53SlII????例9-5列出电路的结点电压方程和回路电流方程。解:+-+-+-2Z10U?21Z3Z4Z1SU?3SU?5SI?1lI?2lI?3lI?53324313)(SSnnIUYUYYUY??????????结点电压方程:回路电流方程122121)(SllUIZIZZ??????334243212)(SlllUIZIZZZIZ???????????UIZZIZll????????35424)(5Z第9章正弦稳态电路的分析3345354313)(SnnnUYUYUYYYUY???????????例9-6列出电路的结点电压方程和回路电流方程。解1lI?3lI?2lI?31333nnSUUUYI???????回路电流方程2611SlUUIZ??????0)(342546?????llIZIZZU???+-+-+-126U?1Z3Z5Z4Z2SU?3SU?3I?343I??2令为参考结点。34513511)(IUYYUYUYnnn??????????21SnUU???的结点电压方程:34另有,据KVL的结点电压方程:1)(33133SnnUUUYI???????321IIIll??????3234324)(SSllUUIZZIZ?????????另有,据KCL33lII???第9章正弦稳态电路的分析aoOCUIrU??????2例9-7求所示一端口的戴维宁等效电路。解12'IIIO?????据KVL,得开路电压:用