Hiroyasu Shimoji

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

E&S2 model for vector magnetic hysteresis property

Abstract This paper presents a new modeling of the vector magnetic property with an integration term. Recently the studies of the two-dimensional magnetic property have made progress rapidly and those achievements have become a center of attraction. The magnetic materials can be measured using the two-dimensional magnetic measuring technique. We enable the magnetic field analysis, which considered the anisotropy, by combining the finite element method and a new E&S 2 (Enokizono, Soda and Shimoji) modeling. A good convergence characteristics by using conventional molding was hard to obtain in the calculation process. This new modeling can improve the defect of the E&S modeling. This paper shows the comparison of the experimental results with the calculated results by using the new modeling.

A new modeling of the vector magnetic property

This paper presents a new modeling of the vector magnetic property with an integration term. Recently, the studies of the two-dimensional (2-D) magnetic property have made progress rapidly and the achievements have become a center of attention. The 2-D magnetic measuring technique shows us practical vector constitutive relations in magnetic materials. We enable the magnetic field analysis, which considered the anisotropy, by combining the finite-element method and a new Enokizono, Soda, and Shimoji (E&S/sup 2/) modeling.

Effect of stator construction of three-phase induction motors on core loss

This paper presents the iron loss analysis of three-phase induction motors. It is necessary to consider the detailed magnetic characteristics inside induction motors to minimalize and optimize the losses. Therefore, the authors examined the loss distribution by the finite element method considering the two-dimensional magnetic properties to develop higher efficiency induction motors.

Iron loss and magnetic fields analysis of permanent magnet motors by improved finite element method with E&S model

In this paper iron loss analysis of the permanent magnet motor considering anisotropy of magnetic material is carried out. The magnetic material can be measured using vector quantity technique. Non-oriented silicon steel sheets for the iron core material have the anisotropy. Therefore, it is necessary to carry out the analysis considering the anisotropy of the magnetic material. A magnetic field analysis, which considers the anisotropy by combining finite element method with the E&S (Enokizono and Soda) model, is considered.

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

Measurement of Core-Loss Distribution Using Thermography

In recent years, high-power electric motors have been mounted on mobile platforms such as electric vehicles. These motors are required to be compact, lightweight, and highly efficient. The reduction of core loss that occurs in electrical steels is an important factor in efficiency. Because core loss is ultimately converted into heat, it can be estimated by measuring the amount of heat generated. Methods for directly measuring the core loss in electrical steel sheets with thermistors and thermocouples have been proposed, but in these methods, many constraints complicate the measurements. In addition, the measurements are not suitable for a large number of sampling points. The aim of this study is to measure the distribution of core loss in electrical steel sheets by using thermography.

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.

Measurement of Local Vector Magnetic Properties in Laser Scratched Grain-Oriented Silicon Steel Sheet With a Vector-Hysteresis Sensor

This paper presents measured local vector magnetic properties in a transformer type model core made of a laser-scratched grain-oriented electric steel sheet by using a vector-hysteresis (V-H) sensor. The V-H sensor consists of B-needle probes for measurement of the magnetic flux density vector B and double H-coil for measurement of the field strength vector H. The distance between the B-needle probes was shortened to be 2.5 mm and a 2 mm × 2 mm-sized double H-coil was mounted on the sensor head to realize higher resolution. The measurement accuracy of the B-needle probes was confirmed with a spatial probe, which can change the needle distance from 2 mm to 20 mm. The results show that the detailed local two-dimensional vector magnetic properties depending on laser-scratches are measurable with the developed new sensor.