Takeru Sato

Improvement of Integration-Type Dynamic E&S Modeling

This paper presents an improved integration-type E&S modeling for applications under high magnetic flux density conditions. In the conventional integration-type dynamic E&S modeling, we assumed linear increment of higher harmonic components including in the magnetic field strength waveforms versus the magnetic flux density. However, the higher harmonic components decrease after getting a peak value in the rotational magnetization process around the saturation region (1.5-1.8 T). The integration-type dynamic E&S modeling was improved with the measured database, and the verification with a simple problem for high magnetic flux conditions was demonstrated in this paper.

Comparison of Iron Loss Characteristics of Divided Cores Considering Vector Magnetic Properties

This paper presents iron loss distributions in divided-stator model cores calculated with the finite-element method considering vector magnetic properties. The magnetic anisotropy and rotational iron loss were considered using the dynamic E&S modeling. In this paper, we discuss the differences of the calculated results depending on the direction of the magnetic anisotropy in the divided cores. Moreover, the effect of difference of the junction position of the divided-stator cores on the total iron loss is investigated.

Evaluation of stator core loss of high speed motor by using thermography camera

In order to design a high-efficiency motor, the iron loss that is generated in the motor should be reduced. The iron loss of the motor is generated in a stator core that is produced with an electrical steel sheet. The iron loss characteristics of the stator core and the electrical steel sheet are agreed due to a building factor. To evaluate the iron loss of the motor, the iron loss of the stator core should be measured more accurately. Thus, we proposed the method of the iron loss evaluation of the stator core by using a stator model core. This stator model core has been applied to the surface mounted permanent magnet (PM) motors without windings. By rotate the permanent magnet rotor, the rotating magnetic field is generated in the stator core like a motor under driving. To evaluate the iron loss of the stator model core, the iron loss of the stator core can be evaluated. Also, the iron loss can be calculated by a temperature gradient. When the temperature gradient is measured by using thermography camera...

Magnetic characteristic analysis of SPM motor by means of dynamic E&S modeling

To make clear iron loss distributions in a stator core of SPM motor under high flux density condition over 1.3T, the integral-type dynamic E&S modeling is employed. The magnetic property database for this analysis is newly prepared in the measurements of the vector magnetic properties of the core material under high flux density conditions up to 1.8T, and then the magnetic reluctivity and hysteresis coefficients of the integral-type dynamic E&S modeling are derived. The results show that there is an applicable region of the integral-type dynamic E&S modeling to obtain a good convergence. We also point out some problems encountered in applying integral-type dynamic E&S modeling.

Improvements of Feedback Control Algorism in Two-Dimensional Vector Magnetic Property Measurements

This paper presents comparison of feedback control algorisms of magnetic flux conditions in two-dimensional vector magnetic property measurements under high magnetic field over 1.6 T. In order to develop a fast measurement algorism, several PID feedback control methods were tested. The results show that the proportion-derivative precedence type (I-PD) control is suitable for reduction of measurement times in vector magnetic property measurements.