モータコア損やトルクリップルを低減するため

Outcome：

2023
ファジー制御を用いて所定の特性を導くことができることを示した

（1）PWM変調、PAM制御方式
（2）Si,SiC,GaNインバータ励磁
（3）インバータ,デッドタイム適応アルゴリズム

Outcome：

2023
PAM制御にて実験を行った

パワエレでの高周波対応のためMHz帯応用の磁気デバイス用磁性体の研究をしている。1μm厚鋼板を試作しB-H曲線など磁気特性を計測している。

Outcome：

2023
μmオーダの鋼板にてインダクタを試作してその有効性を確認した

2022
単ロールー圧延法にてμmオーダの鋼板を試作し高周波磁気特性を計測した。

医療、家電で年率5-16％世界市場が拡大している小型モータ駆動システムは、機上置となることが多いので、更なる小型軽量高効率化を目指す

Outcome：

2020
We have presented a detailed assessment of core loss, copper loss and magnetic flux density of the interior permanent magnet synchronous motor (IPMSM) with pulse-amplitude modulation (PAM) inverter under different excitation angles in both no-load and load conditions. The PAM method automatically controls the amplitude of changeable DC-link voltage, and the excitation angle for switches in the inverter is varied from 120 degree to 180 degree according to a twelve-step switching pattern designed particularly for the PAM-based inverter of IPMSM. In addition, for reference purpose, the pulse-width modulation (PWM) inverter excitation with a fixed DC-link voltage, very high voltage modulation index and carrier frequency of 10 kHz for the IPMSM is additionally performed in all experiments of this study. Various conditions with changes in speed and torque are examined.
Experimental results show that harmonic components produced by the PAM inverter in the IPMSM current, voltage and magnetic flux density have large effects on the motor core and copper losses; physics-based explanations and insights are also presented. The PAM under 135 degree excitation angle has excellent performance in reducing IPMSM core and copper losses since it can significantly decrease the harmonic components in motor current, voltage and magnetic flux density. Furthermore, simulations using finite element method (FEM) are conducted to validate experimental results of IPMSM core loss with the PAM excitations. With the ability to reduce harmonic component magnitudes, the PAM 120 degree and PAM 135 degree excitations have outstanding efficiency in the no-load and load conditions, respectively.

2022
We have experimentally analyzed the core loss characteristics of an interior permanent magnet synchronous motor (IPMSM) excited by a SiC inverter with the sinusoidal pulse-width modulation (PWM) and high modulation index of 1.1 considering the mutual effects of the high carrier frequencies of up to 200 kHz, different dead-times of 250 and 1000 ns, control sample times of 100–1000 μs, and stator core temperature. The experimental IPMSM drive system is operated in load condition with a torque of 1.05 Nm and rotational velocity of 1500 rpm. Furthermore, the ringing phenomenon and rise time in the motor voltage are measured and analyzed using a high-resolution oscilloscope that has a superior sampling rate of up to 5 giga-samples per second (GS/s), which helps to thoroughly examine the impact of the SiC inverter excitation on the motor core loss. The relations of the total harmonic distortion (THD) of the measured motor voltage and current and the distortions in the magnetic flux density through the stator core to the IPMSM core loss properties are also evaluated. Moreover, the explanations and insights based on physics of the obtained results are presented.
From the experimental analysis with our motor drive system, the following key points are summarized:
(a) It is useful to employ the high-resolution oscilloscope whose sampling rate is high of up to 5GS/s to properly measure the quick rise time and high ringing frequency in the IPMSM voltage as around 15.2 ns and 5.8–6.2 MHz, respectively, as well as to effectively analyze the distortions in the motor current, voltage and flux density.
(b) When the carrier frequency rises from 10 kHz to 100 kHz, the IPMSM core loss decreases relatively much since the skin effect is dominant in this condition. However, once the carrier frequency is from 100 kHz to 200 kHz, the overall impact of the harmonics and ringing phenomena in the IPMSM current and voltage and the distortions in the flux density through the stator core becomes significant. Because the overall impact is almost equivalent to that of the skin effect, the motor core loss changes slightly in this case.
(c) The dead-time of the SiC inverter has a small effect on the IPMSM core loss. Whereas, the control sample time has a relatively large effect on the motor core loss, especially in the case with a high carrier frequency of 200 kHz. When the control sample time is from 800 μs to 1000 μs, the harmonics in the motor current and voltage and the distortions in the flux density become substantial; these cause the remarkable increase in the motor core loss.