Ruia+Rzip=usu Rzia+R2ip=us22 Usli R Us1-Us2 us2-Us3 i2= s22 R22 Ru R12 △ △ R21 Rz2 △ Re+R2W,2+ △ △ 证得 ia=ial+ia2+ia3 即回路电流满足叠加定理 ib ia R2 + – R3 + – R1 + – us1 us2 us3 i1 R11ia+R12ib =us11 R21ia+R22ib =us22 ǻ ǻ s s a s22 12 s11 22 21 22 11 12 22 22 11 12 u R u R R R R R u R u R i   s3 12 s2 12 22 s1 22 u R u R R u R ǻ ǻ ǻ    us1-us2 us2-us3 ia = ia1 + ia2 + i 䇱ᗇ a3 ণഎ䐟⭥⍱┑䏣ਐ࣐ᇊ⨶