Abstract：To research the effect of the armature reaction on the applied permanent magnet of a liquid metal magnetohydrodynamic (LMMHD) generator,the 3D finite element method is adopted to calculate and analyze the magnetic field’s distribution,permanent magnet’s flux density working point,and the working air-gap flux density under different armature currents in order to find out the armature reaction characteristics of the LMMHD generator.The results show that the induced magnetic field generated by the armature current distorts the working air-gap magnetic field,causes the magnetic saturation of the ferromagnetic parts,enlarges the magnetic flux leakage,and produces serious demagnetization effect in the permanent magnet.The effective magnetic field in the working air-gap decreases and the end leakage magnetic field increases with an armature current when the applied magnetic field reaches the magnetic saturation.There also presents the Y-direction magnetic field in the middle area of the working air-gap with an X-direction armature current.
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2015, Vol. 30 
