Measurement of Three-Dimensional Magnetostriction on Grain-Oriented Electrical Steel Sheet
This paper deals with the magnetostriction of a grain-oriented electrical steel sheet measured by using the two-dimensional vector magnetic property measurement system and a three-axial strain gage. The magnetostrictions in arbitrary direction are calculated with the measured strain tensors. The magnetostriction characteristics were changed depending on the magnetization process according to the exciting magnetic flux density and the exciting direction. In this paper, we make clear the relationship among the two-dimensional magnetostriction, the magnetic flux density vector, and the magnetic field intensity vector in the grain-oriented electrical steel sheet.
The development of high-efficiency, low-loss motors is required for industrial and automotive applications. We propose that motors with high efficiency and low loss can be developed by controlling the vector magnetic properties of non-oriented electrical steel sheets by applying stress. Therefore, it is necessary to examine not only the magnitude of the magnetic field strength but also the spatial phase difference between the B and H vectors under stress. In this paper, we present a measurement system that we developed to clarify the relationship between stress and vector magnetic properties.
To improve the efficiency of electric motors, we developed the excitation inner core method to evaluate the magnetic properties such as the iron loss of the actual stator core. After preparing two stator cores with a frame, we examined the frames influence of compressive stress by applying the standard and small excitation inner core methods to evaluate the iron loss of both stator cores having a frame. After removing the frames of the two stator cores, we evaluated the iron loss of two stator cores without the frames again by applying both methods.
This paper presents Vector B-H tester. Vector magnetic characteristics can express the vector relationship between magnetic flux density vector and magnetic field strength vector. A precise measurement method of vector magnetic characteristics has been imposed. However, this method spends time and requires an effort to prepare the measurement. Vector B-H tester can easily measure and evaluate the vector magnetic characteristics.
Permanent magnets, especially Nd-Fe-B magnets are very important engineering elements that are widely used in many applications. Detailed design of electrical and electronic equipment using permanent magnets requires precise measurement of magnetic characteristics. We developed a measurement system which can measure the magnetic characteristics of permanent magnets precisely. This paper presents the measured results of magnetic characteristics of various types of permanent magnets and comparison of these characteristics.