4.2相量法的基本概念 (3)几种常用关条: j2=-1,j3=-j,j4=1,1/j=j ej0°=j,e-j90=-j,e±j180°=-1 1+j=V2∠45°1-j=2∠-45° -1+j=V2∠135°-1-j=V2∠-135° 1+j2=V5L63.4°2+1=V5L26.6° j 2 = -1 , j3 = -j , j4 = 1 , 1/j = -j e j90°= j , e -j90°= -j , e ±j180°= -1 (3) 几种常用关系: − + = − − = − + = − = − 1 2 135 1 2 135 1 2 4 5 1 2 4 5 j j j j 1 + j 2 = 5 6 3 .4 2 + j1 = 5 2 6 .6 4.2 相量法的基本概念