Evaluation of the Iron Loss Distribution of the Actual Stator Core Using Small Excitation Inner Cores

To obtain the basic data to manufacture the highly effective rotating machine, the axial iron loss distribution of an actual stator core of the complex structure was evaluated by using the small excitation inner core. The laminated thickness of this small excitation inner core is approximately 1/6 of the thickness of the stator core. Therefore, the circumferential iron loss distribution and the axial iron loss distribution of a stator core can be measured by using this small excitation inner core. Then, to compare the difference of the axial iron loss distribution in the stator core, we investigated the axial iron loss distribution in the actual stator core after two manufacturing processes, the laminating process and the shrink-fitting process. Iron loss of two stator cores was measured in three places (the edge, the quarter part, and the center). The result of our investigation showed that the axial iron loss distribution in the actual stator core clearly changed. This paper reports on the axial iron loss distribution in two manufacturing processes in two actual stator cores measured by using the small excitation inner core.