12 22 12 d dΦ 自感电压l2 N 22 dt dt dt 互感电压 dp dΦ 12 =M12 dt 可以证明:M1=M21=M。+ u12 – + u22 – i2 12 22 N1 N2 22 22 2 22 22 2 2 2 2 12 12 2 12 12 1 12 12 2 d d d ( ) d d d d d d ( ) d d d i u N L L t t t i i u N M M t t t i = = = = = = = = 自感电压 互感电压 可以证明:M12= M21= M