Shinya Urata

Magnetic characteristic analysis of the motor considering 2-D vector magnetic property

In this paper, influence of the magnetic properties on rolling direction of the nonoriented electrical steel sheets were examined. We have carried out the magnetic field analyses considering the two-dimensional vector magnetic properties in the stator core of a condenser motor. The finite element method (FEM) considering Enokizono, Soda, and Shimoji modeling was used in these analyses

The calculation considered two-dimensional vector magnetic properties depending on frequency of transformers

In this paper, the two-dimensional vector magnetic properties depending on the exciting frequency are made clear by using the finite element method (FEM) and the Enokizono, Soda, and Shimoji (E&SS) modeling as an anisotropic material modeling. In the investigations, a 3-phase 3-leg transformer model is analyzed under some exciting frequency conditions

Vector magnetic characteristic analysis of electrical machines

The paper describes the vector magnetic characteristic analytical method using the vector magnetic hysteretic engineering model. By this method, various kinds of vector magnetic properties, for example vector hysteretic loop, coercive force, magnetic power loss, vector behavior of magnetic flux density B, and magnetic field strength H, can be obtained on electrical machines and apparatus.

Magnetic Characteristic analysis considering the crystal grain of grain-oriented electrical steel sheet

This paper presents the two-dimensional vector magnetic property of the grain-oriented electrical steel sheet. The local magnetic characteristics are varied with the interaction of domain structure in the crystal grains, because the grain-oriented electrical steel sheets are composed of many crystal grains. Therefore, it is necessary to evaluate the local magnetic characteristic of electrical steel sheet to improve the magnetic properties. However, the local magnetic characteristic, including hysteresis, was difficult to express numerically with the conventional constitutive relation. In this paper, the influence of the specific magnetic permeability of the grain boundary on the magnetic power loss properties has been investigated numerically. In the numerical simulation, the finite-element method with the E&SS modeling is used to consider the grain structure and its orientation.

Dynamic vector magneto‐hysteretic E&S model considering eddy current effect

Purpose – The purpose of this paper is to show formulation of a dynamic E&S model, which enables analysis of the effects of eddy currents under vector magnetic behavior in numerical simulations and to demonstrate its usefulness.Design/methodology/approach – When a magnetic flux waveform is distorted, effects of eddy currents increase due to harmonic flux components. In such a case, the result calculated by using the conventional E&S model does not agree with the measured one. The conventional E&S model is improved by considering magnetic flux waveform distortion. The harmonic components of the magnetic field strength waveform were estimated with the classical eddy current model.Findings – In the verification of the dynamic E&S model, it was found that the magnetic field was suppressed by the effect of the eddy current. The conventional analysis overestimates the magnetic field, because the magnetic flux waveform cannot distort. In the magnetic characteristic analysis of a three‐phase transformer model cor...

Development of the apparatus for measuring magnetic properties of electrical steel sheets in arbitrary directions under compressive stress normal to their surface

In designing motors, one must grasp the magnetic properties of electrical steel sheets considering actual conditions in motors. Especially important is grasping the stress dependence of magnetic power loss. This paper describes a newly developed apparatus to measure two-dimensional (2-D) magnetic properties (properties under the arbitrary alternating and the rotating flux conditions) of electrical steel sheets under compressive stress normal to the sheet surface. The apparatus has a 2-D magnetic excitation circuit to generate magnetic fields in arbitrary directions in the evaluation area. It also has a pressing unit to apply compressive stress normal to the sheet surface. During measurement, it is important to apply uniform stress throughout the evaluation area. Therefore, we have developed a new flux density sensor using needle probe method. It is composed of thin copper foils sputtered on electrical steel sheets. By using this sensor, the stress can be applied to the surface of the specimen without influence of this sensor. This paper described the details of newly developed apparatus with this sensor, and measurement results of iron loss by using are shown.In designing motors, one must grasp the magnetic properties of electrical steel sheets considering actual conditions in motors. Especially important is grasping the stress dependence of magnetic power loss. This paper describes a newly developed apparatus to measure two-dimensional (2-D) magnetic properties (properties under the arbitrary alternating and the rotating flux conditions) of electrical steel sheets under compressive stress normal to the sheet surface. The apparatus has a 2-D magnetic excitation circuit to generate magnetic fields in arbitrary directions in the evaluation area. It also has a pressing unit to apply compressive stress normal to the sheet surface. During measurement, it is important to apply uniform stress throughout the evaluation area. Therefore, we have developed a new flux density sensor using needle probe method. It is composed of thin copper foils sputtered on electrical steel sheets. By using this sensor, the stress can be applied to the surface of the specimen without infl...