1.2线电压与相电压的关系 (1)Y接 A 设UN=UA=U∠0 ABIOCA B UBN=U/B=U∠-120° B UN=UC=U∠120° B i BC C Um=UN-U=U∠0°-U∠-120°=√3U30° BN UcN=U∠-1200-U∠120°=√3UZ-90 =U-N=U∠120°-U∠0°=√3U∠150°(1) Y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 CN 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 90 0 120 3 30 = − =  −  =  = − =  − −  =  − = − =  −  − =  • • • • • • • • • U U U U U U U U U U U U U U U U U U 11.2 线电压与相电压的关系