2.对称三相电源,线电压与相电压的关系: A,星形连接(Y连接) i 相电压 A 设UAN=UA=U∠0° UA UAB UCA UBN=UB=UL-120° o N B Ucx=Uc=U∠120° 线电压 U=UAN-UBN=U∠0°-UL-120°=V3U∠30° Ux=jgN-jcw=UL-120°-U∠120°=3U∠-90° icA=Ucx-UaN=U∠120°-UL0°=V3UL15092.对称三相电源,线电压与相电压的关系: A,星形连接(Y连接) A + – X B C Y Z A B C N A U B U C U AB U BC U CA U A I B I C I o C N C o B N B o AN A 120 120 0 U U U U U U 设 U U U o o o C A C N AN o o o BC BN C N o o o AB AN B N 120 0 3 150 120 120 3 9 0 0 120 3 3 0 U U U U U U U U U U U U U U U U U U 相电压 线电压