著者

Yuki Shimizu Shigeo Morimoto Masayuki Sanada Yukinori Inoue

出版者

The Institute of Electrical Engineers of Japan

雑誌

IEEJ Journal of Industry Applications (ISSN:21871094)

巻号頁・発行日

vol.10, no.5, pp.554-563, 2021-09-01 (Released:2021-09-01)

参考文献数

19

被引用文献数

7

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Interior permanent magnet synchronous motors (IPMSMs) have been widely used as traction motors in electric vehicles. Finite element analysis is commonly used to design IPMSMs but is highly time-intensive. To shorten the design period for IPMSMs, various surrogate models have been constructed to predict relevant characteristics, and they have been used in the optimization of IPMSM geometry. However, to date, no surrogate models have been able to accurately predict the characteristics over the wide speed range required for automotive applications. Herein, we propose a method for accurately predicting the speed-torque characteristics of an IPMSM by using machine learning techniques. To improve the prediction accuracy, we set the motor parameters as the prediction target of the machine learning methods. We then used the trained surrogate model and a real-coded genetic algorithm to minimize the volume of the permanent magnet and showed that the design time can be significantly reduced compared with the case where only finite element analysis is used.

著者

Suzuka Sasayama Yuki Shimizu Shigeo Morimoto Yukinori Inoue Masayuki Sanada

出版者

The Institute of Electrical Engineers of Japan

雑誌

IEEJ Journal of Industry Applications (ISSN:21871094)

巻号頁・発行日

pp.22007240, (Released:2023-01-13)

被引用文献数

1

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Interior permanent magnet synchronous motors (IPMSMs) are used for various applications and high efficiency control is required. Maximum torque per ampere (MTPA) control is a method to control IPMSMs with high efficiency. However, since the motor parameters vary with magnetic saturation, MTPA control cannot be easily realized. Here in, we propose a fully online and automatic MTPA control method. To find the MTPA point while driving the motor, it is necessary to predict the entire flux linkage surface. Therefore, the flux linkage surface is approximated by a plane from the sensor information at a specific current condition that considers the effect of magnetic cross-saturation. MTPA control is achieved using the estimated flux linkage plane and the gradient ascent method. The simulation results reveal that the torque maximized in two search periods, which was completed in 0.06 s. The proposed method is effective for a wide current range.

著者

Yuki Shimizu Shigeo Morimoto Masayuki Sanada Yukinori Inoue

出版者

The Institute of Electrical Engineers of Japan

雑誌

IEEJ Journal of Industry Applications (ISSN:21871094)

巻号頁・発行日

vol.6, no.6, pp.401-408, 2017-11-01 (Released:2017-11-01)

参考文献数

11

被引用文献数

4 22

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Nowadays, interior permanent magnet synchronous motors (IPMSMs) are widely utilized as traction motors. The permanent magnets used in IPMSMs are an important factor; thus, high-coercivity permanent magnets with lesser rare-earth elements are in development. This study investigated the performance of IPMSMs typically used in automotive applications modified to contain a strong magnet model (SMM). Rotor models with two permanent magnet arrangements, that is, a V-shaped single-layered permanent magnet structure (Type 1V) and a double-layered permanent magnet structure (Type 2D), were considered in this study. This paper discusses the characteristics of the analysis models based on the results of a two-dimensional finite element analysis. The maximum torques of Types 1V and 2D with the SMMs were approximately the same. In addition, the loss of Type 2D with the SMM was lower than that of Type 1V with the SMM at two evaluation points and under two driving schedules. Therefore, Type 2D was proved to be suitable for use with the SMM.

著者

Marika Kobayashi Shigeo Morimoto Masayuki Sanada Yukinori Inoue

出版者

The Institute of Electrical Engineers of Japan

雑誌

IEEJ Journal of Industry Applications (ISSN:21871094)

巻号頁・発行日

vol.10, no.6, pp.675-681, 2021-11-01 (Released:2021-11-01)

参考文献数

24

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Irreversible demagnetization analysis is complicated in motors with bonded magnets that have unique B-H curves and do not exhibit distinct knee points. We have proposed a permanent magnet assisted synchronous motor (PMASynRM) with bonded magnets and examined its demagnetization characteristics by assuming the relative recoil permeability (μrec) as constant to simplify the analysis. However, the present recoil loop measurements of bonded magnets show that μrec has different characteristics depending on the magnitude of the reverse magnetic field intensity at the working point of the magnet and temperature. Therefore, this study presents a demagnetization analysis method based on these measurement results and investigates the demagnetization characteristics of a PMASynRM considering the variation in μrec for bonded magnets. The results of the demagnetization analysis considering the variation in μrec are compared with those where μrec is assumed to be constant. The comparison results indicate that there is no problem with assuming a constant μrec of 1.15 in the demagnetization analysis of a motor with bonded magnets.

著者

Tatsuhiko Urakami Shigeo Morimoto Yoshikazu Nitadori Kensuke Harada Misao Owada Teruo Kitagawa

出版者

日本小児内分泌学会

雑誌

Clinical Pediatric Endocrinology (ISSN:09185739)

巻号頁・発行日

vol.16, no.2, pp.53-58, 2007 (Released:2007-05-17)

参考文献数

18

被引用文献数

2 2

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This study evaluated recent changes in the annual incidence of childhood type 2 diabetes in the Tokyo metropolitan area. From 1974 to 2004, a total of 236 students were diagnosed as having type 2 diabetes by the urine glucose screening program at school. The overall incidence of type 2 diabetes was 2.55/100,000. Overall, 83.9% of students with diabetes were obese; junior high school students had a significantly higher incidence than primary school students (0.75 vs. 6.27/100,000). The annual incidences over the 5-yr periods from 1974-2004 were 1.73, 3.23, 3.05, 2.90, 2.70 and 1.41/100,000, respectively. The incidences in 1974-1980 and 2001-2004 were significantly lower than those in 1981-1985, 1986-1990 and 1991-1995, because primary school students in 1974-1980 had a significantly lower incidence (0.27/100,000), and junior high school students in 2001-2004 had a somewhat lower incidence (3.66/100,000) than during 1981-2000. In recent years, Japanese children's lifestyle and eating habits have gradually improved, and this may have contributed to the trend toward decrease in the incidence of type 2 diabetes in 2001-2004 in the Tokyo metropolitan area.