C 设ua,li,i12.为状态变量 C R C LI R LI dt LI u C lI1+I dt LI L2 L2 dt LI c +ictus L2 R R LI TLL2 消去非状态量 R L2 l1=u-(in1+i2)R1+设uc , iL1， iL2为状态变量 C C S L u i R u dt di L = + 1 + 1 1 L R L u R i dt di L 1 2 2 2 = − 消去非状态量 ic= - (iL1 +iL2 ) iR = is +iL2 uL1= uc -(iL1 +iL2 )R1 +us L1 L2 C i i dt du −C = + C C i dt du C = 1 1 1 L L u dt di L = 2 2 2 L L u dt di L = us R 1 C L1 L 2 R 2 i s - + uC iL2 iL1 iR + - iC