(3)Ux=U1/3:≈220 设 220/0°V ZNU 则in=U/z71=1903-3687°A=1522142A 12=U4/Z2=1298-2836°=1142-166A 14=n+12=2664-17.58=392/-3342°A UA=ZA+U=0.36563°×3192/-3342°+220 =1149289+420=230.59+1.47=230.63/11y ∴电源侧线电压=√3×23063=39946 闪四 西南交通大学西南交通大学 ∴ 电源侧线电压 （3） UA¢ =Ul 3 » 220V 设 U& A¢ = 220 0° V =15.22 - j11.42A I & A2 = U& A¢ / Z2 = 12.98 - 28.36° = 11.42 - j6.16A I & A = I & A1 + I & A2 = 26.64 - j17.58 = 31.92 - 33.42° A \ = + ¢ = 0.36 56.3°´ 31.92 - 33.42° + 220 A l A U A U Z I & & & = 11.49 22.89° + 220 = 230.59 + j4.47 = 230.63 1.11°V = 3 ´ 230.63 = 399.46V 则 I & A1 = U& A¢ Z1 ¢ = 19.03 - 36.87° A Zl Z2 Z1 ¢ A1 I & A2 I & + - U A & + - U A¢ & A I &