A research of efficiency improvement by means of wedging with soft ferrite in small induction motors

To save electric power to be consumed in small induction motors, its efficiency improvement is required. As one of methods to improve the efficiency of small induction motors, magnetic materials have been wedged into the stator slots of the induction motors. Experiments have been performed on fabricated induction motors with soft ferrite wedged into stator slots. As the results, the decreasing of starting torques for the induction motors was found to be only 3 %. The efficiency of the ferrite wedged induction motors was improved by about 4 % at the rated output and 11 % at a quarter output, as compared with that without the soft ferrite.