方法二: 209 C U=8U/1+2(+1) 8U1 =U1-j201 另:U1=Us-l1=5∠0°- Us(5∠029 2+35∠0° b 5-j20 U=5∠0 1+j20 2+35∠0°) 5-j20 1+j20 2+j40 ×35 5-j20 5-i20方法二: 1 1 1 1 20 8 2( ) U j I U U I I U S 8 1 U j20 2 1 + - + - 1 U I 1 I U a b 5 0 V 5 20 2 35 0 1 j I I 则: 1 1 5 0 1 U U S I I 另: I j j j j I j j U 5 20 2 40 35 5 20 1 20 5 (2 35 0 ) 5 20 1 20 5 0