(2)反接串联 iR,L∠M R Q =R+48N+h dt di-M di+Ri dt -(R+R,r++山-20=R+ d R=R+R2 L=L1+L2-2M L=L,+L,-2M≥0→M≤，+L) 互感不大于两个自感的算术平均值