Reduction of Iron Loss on Motor Stator Cores by Means of Secondary Current Heating Method

In this article, the “secondary current heating method,” which has been proposed in the previous articles, was used to heat-treat the laminated stator cores of actual motors to reduce the iron loss. To evaluate the magnetic properties of the laminated stator cores including the teeth, an inner core was installed inside the stator to form a closed magnetic path with the two teeth, back yoke, and inner core. The air gap between the stator and the inner core causes the loops to be tilted compared to the B–H loop of the back yoke, though it was found that the iron loss was reduced by about 30% in the laminated stator core after heat treatment.