92阻抗(导纳)的串联和并联 阻抗的串、并联在形式上与电阻的串联、并联相同 例:RLC串联电路R=159L=12mHC=5uf u=1002c0s(5000,求瞬时表达式和各元件的电压相量 +1 Jac 解U=100∠0°Zn=1592Z=j 0CJ402Z=J0L=j00 Zn=za+Z+Z=(15+j20)=25∠3.13(感性阻抗) i=Us_100∠0 4∠-53.13U=RI=60∠-53.13 25∠53.13 UL=joLI=240∠3687° U=ii=160∠-14313”i=42cos(5000-5313)阻抗的串、并联在形式上与电阻的串联、并联相同 例：RLC串联电路R=15Ω L=12mH C=5 μf u = 100 2cos(5000t)v,求i瞬时表达式和各元件的电压相量 I 160 -143.13 i 4 2cos(5000t 53.13 )A c 1 U -j 4 53.13 U RI 60 53.13 25 53.13 100 0 z Us I z z Z Z (15 j20) 25 53.13( ) -j40 z j L j60 c 1 U 100 0 Z 15 Z -j 0 0 C 0 R 0 0 0 eg eg R L C R C L 0 =  = −  = =  − = =  −   = = = + + = + =  =  =  =  =  =  =      感性阻抗 解 · · · · R + - jωL + - + - U  I  UR  UL  UC  j c 1  + -。 。 9-2 阻抗（导纳）的串联和并联 0 U  L = jLI  = 24036.87