Experimental assessment of the annealing effects on magnetic core of fractional power synchronous reluctance motors

The paper deals with experimentally-based comparative analyses aimed at quantifying the annealing process effects on the magnetic core properties of small synchronous reluctance motors. For this purpose, `ad hoc' prototypes have been produced by adapting two twin normal-production, 120 W, line-start synchronous machines and, for one of them, the stator and rotor cores have been annealed. As an attempt to discriminate the iron losses reduction due to the annealing, no-load tests with sinusoidal supply have been performed, while the magnetizing currents and the related torque capability of the machines is also approached measuring their flux mappings (magnetic models). Finally, the performed tests have been replicated using 2D finite element method models that include the damaged material zones in the lamination edges due to the punching. Very good agreements between measurement and simulation results have been obtained.