11i1单口网络的导纳+111U1111111O11111E/复导纳的模导纳角111i11Y,=G+iB三L011U花11111复导纳1电纳电导11福1-I Y = /G? +B?福1G=YcosP y或1B1=arctan.GB=Ysinβ y11/11/11
或 G=|Y|cos y B=|Y|sin y 2 2 | | arctan y Y G B B φ G = + = j y I Y Y G B U = = = + 复导纳 电导 电纳 复导纳的模 导纳角 I + - U N ➢ 单口网络的导纳
阻抗(导纳)的串联和并联1①阻抗的串联1Ti+U1 -1T1EP+1+Z1+Z2uZu0,粘Zn1/Un+一U-U, +U, +..-+U,一n= I(Z, + Z,IZ---+ Z.)+-福福Z:: Z=z,=(R +jX)UZk=lk=l
◆ 阻抗(导纳)的串联和并联 1 1 ( ) n n k k k k k Z Z R jX = = = = + ①阻抗的串联 1 2 1 2 ( ) U U U U I Z Z Z IZ = + + + = + + + = n n i i Z U U Z =
②导纳的并联ii十IG+UYY2怡UYUY-1+Y+Y一一YY=Y =Z(G,+jB.)1福Y酒Z,Z,Z两个阻抗Z}、Z,的并联等效阻抗为Z, + Z2
= = = = + n k n k Y Yk Gk Bk 1 1 ( j ) ②导纳的并联 两个阻抗Z1、Z2的并联等效阻抗为: 1 2 1 2 ( ) n n I I I I U Y Y Y UY = + + + = + + + = i i Y I I Y = 1 2 1 2 Z Z Z Z Z = +
袁祥例求图示电路的等效阻抗@ = 105rad/s-o解感抗和容抗为:30g11110021111mH11T1111U.H1111111Xl = @ L= 105 ×1×10-3=100Q1E111.超11111111X:-1002Y105 ×0.1×10-6oC--111111111-福jX,(R + jXc)j100 ×(100 - j100)Z=R30H1100jX, +R +jXc烧11111111111= 130 + j100Q1I1111
例 求图示电路的等效阻抗, =105 rad/s 。 解 感抗和容抗为: 5 3 10 1 10 100 X L L − = = = 5 6 1 1 100Ω 10 0.1 10 XC C − = − = − = − 2 1 2 j ( j ) j100 (100 j100) 30 j j 100 130 j100Ω L C L C X R X Z R X R X + − = + = + + + = +
袁例图示电路对外呈现感性还是容性?1111解等效阻抗为:11-j623215(3 + j4)1T1Z = 3- j613j4Q5215 + (3 + j4)1125Z53.10132= 3 - j68 + j411111= 5.5 - j4.75QI11一一1111/1电路对外呈现容性1111-福11111111111111111111111111111I1111111
例 图示电路对外呈现感性还是容性? 解 等效阻抗为: 电路对外呈现容性 0 5(3 j4) 3 j6 5 (3 j4) 25 53.1 3 j6 8 j4 5.5 j4.75 Z + = − + + + = − + + = −