Interior type permanent magnet synchronous motor analysis by equivalent circuits

Experimental tests show that steady-state core loss of interior-type permanent magnet machines changes with the terminal voltage in a peculiar way due to flux redistribution produced by armature reaction. An equivalent circuit is proposed to predict such loss through new parameters that can be easily determined by experimental tests. Different operating conditions of the motor such as under demagnetizing or magnetizing armature reaction effects and under saturation influence are included in the analysis. The new circuit allows a detailed representation of the interior-type permanent magnetic machines that can be usefully adopted in loss and efficiency computations