(1)RL串联电路瞬时值关系L=Lk+lz 设:i=√2/ sin at 则: iR+ L=√2 RIsin c+√2X, I cos C √2/( Rsin at+ X cos at) √2I√R2+X2sin(o+9) √2lz|sin(an+) √2Usi(a+)m领先i角 其中:U/= 21=、R9=gXy R2 sin( ) 2 sin( ) 2 sin( ) 2 ( sin cos ) 2 sin 2 cos 2 2           = + = + = + + = + = + U t I Z t I R X t I R t X t u RI t X I t L L L 设: i = 2Isint dt di iR L u uR uL = + = + 则: 其中: R X tg −1 L  = 2 2 U = I Z Z = R + XL (1) R-L串联电路瞬时值关系 u领先i 角