In this study, vector magnetic hysteresis characteristics are reported. It is necessary to handle the magnetic characteristic in the vector relation. It can be required that the characteristic value on the hysteresis property is also re-examined. It is necessary to review the conventional magnetic characteristic handling from a vectorial viewpoint. This greatly affects not only electromagnetic field analysis but also materials development.
Electrical steel sheets have been widely employed as a magnetic core material of an electromagnetic equipment. Magnetic materials in the equipment is possible to be excited by two-dimensional AC-magnetization and/or AC-magnetization with two-dimensional DC-biased magnetization. In this paper, the magnetic properties of electrical steel sheets under two-dimensional DC-biased magnetization have been researched. The phase difference of between the fundamental components of B and H under high DC-biased condition becomes very smaller and phase compensation is very important in loss measurement. Also, we found that the magnetic loss under two-dimensional AC-magnetization is very sensitive to magnetic flux density waveform.
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.
It was clarified that not only the tensile and compressive stress but also the shear stress occur on the surface of the motor core. Therefore it is needed to evaluate the magnetic properties of the core material under the various stress condition. In this paper, we will report about influence of the arbitrary stress on the vector magnetic properties of a non-oriented electrical steel sheet under various magnetic flux conditions. From these results, it was clear that the magnetic field strength and magnetic power loss decrease when tensile, compression, and shear stresses are applied.
When compressive stress is applied to electrical steel sheets in their thickness direction, both permeability and magnetic losses change. The stress induced loss reduction was observed both ring and strip specimens, and they are mainly from hysteresis loss change due to the stress. Magnetizing process due to the stress is discussed by means of domain observations.