(0)=0 + (t)=8()V l4()2=x20=L8( d t l!(0)=0 d 604Cn d t+ d t 0)+a6(7)t 闪四 西南交通大学西南交通大学 ε(t)A L + - uL iL i L (0- ) = 0 i L (t) = e (t) V ( ) ( ) ( ) L t dt di t u t L L L = = d C - + δ( uc t)A (0 ) = 0 c - u ò + -¥ + = 1 0 (0 ) i dt C uc c ò ò + - - = + -¥ 0 0 1 0 1 i dt C i dt C c c ò + - = - + 0 0 ( ) 1 (0 ) t dt C uc d C 1 =