2018 年 26 巻 3 号 p. 454-459
To achieve a highly effective electric motor, we are continuously studying the building factor (BF) problem of an electric motor stator core. It is well-known that the magnetic properties of electrical steel sheet used for the electric motor is deteriorated by the residual stress generated when processing it to the stator core. Accordingly, we are investigating the degradation of the magnetic properties of an electric motor stator core by manufacturing processes such as a laminated process, a winding process, a varnishing process, and a shrink fitting process. We are proposing the excitation inner core method to evaluate the magnetic properties of an electric motor stator core. Then, we evaluated iron losses of five actual induction motor stator cores by using the excitation inner core method. This paper reports on the investigated results of the performance deterioration of a stator core caused by manufacturing processes of an electric motor stator core.
