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Development of Reference Shunt for Short‐Time Alternating High Current Tests and Study of Measuring System
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JUNZO KIDA MASATOSHI NAKAJIMA YUTAKA GODA KUNIO KIKUCHI KIETSU KUDO HIROMI ISHII YOSHIHIKO MATSUI TOSHIRO MATSUMURA TATSUO KAWAMURA 《Electrical Engineering in Japan》2016,197(2):23-32
Short‐circuit tests for power circuit breakers and others require alternative short‐time current measurement, from a few kA to over several tens kA. However, the reference measurement system as a national standard or a specified secondary standard instrument to directly perform comparative test as a complete calibration test in high current class has not yet been established globally. The Japan Short‐Circuit Testing Committee (hereinafter referred to as “JSTC”) has therefore developed a shunt resistor that can be used as a standard instrument for high current measurement. Reference system using this shunt resistor is also considered by JSTC. The performance of the newly developed shunt resistor has been checked through several methods, such as resistance measurement, high power current test, high frequency current test, temperature rise test, and interference test. The results of the tests proved satisfactory performance. Resistance of the shunt resistor before and after the tests was invariant and stable. This makes the shunt resistor adequate for a reference in practical use. In addition, evaluation of uncertainty of the whole reference system including this shunt resistor satisfactorily fulfills the requirements of IEC 62475 edition 1.0, 2010. 相似文献
2.
Manufacturing and Control of a Variable Magnetic Flux Motor Prototype with a Mechanical Adjustment Method
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TAKAAKI ISHII TSUYOSHI NONAKA SOHEI OGA MOTOMICHI OHTO 《Electrical Engineering in Japan》2017,199(1):57-66
A new structure and control method for a variable magnetic flux motor (VMFM) is proposed to achieve a high‐efficiency electric vehicle (EV) motor drive under a wide range of conditions. A VFMF prototype that was designed by considering the loss was manufactured and evaluated in an experiment. The prototype demonstrated low iron loss and sufficient max torque. Thus, the prototype can provide a high‐efficiency drive with low output, which is frequently the case for EVs. Map control enables a wide phase angle for the vector‐control drive of the VMFM under a changing magnetic flux. Thus, the VMFM provides a high‐efficiency drive under a wide range of conditions. 相似文献
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TANG ZHENGWEI NAOHIRO ISHII TATSURO OHTAJ TAMOTSU OKADA 《International journal of systems science》2013,44(12):2609-2617
Estimating the frequency of one or more sinusoidal waves is a problem belonging to the field of signal analysis. The frequency characteristics of sinusoidal waves can be measured by peaks or troughs of the waves. Because of (he limit of the sampling frequency, the peaks or troughs of sinusoidal and EEG waves in the sampling usually deviate from their original ones in the time domain. Starting from a sinusoidal wave analysis, we present a correction formula with which the deviation time td can be calculated so as to detect the position of the real peak or trough of the data as fast and as accurately as possible on the time axis. The wave of the sleep spindle in the EEG can be considered as an asymmetrical sinusoid. Then after the waves have been filtered, the formula can also be applied to analyse the spindle of EEG waves and it is shown to be useful in the measurement of the frequency of the spindle wave. Error analysis and practical examples are presented. 相似文献
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M. ICHIMURA T. CHO H. HIGAKI M. HIRATA H. HOJO T. IMAI K.ISHII M. K. ISLAM A. ITAKURA I. KATANUMA J. KOHAGURA Y. NAKASHIMA T. NUMAKURA T. SAITO Y. TATEMATSU M. WATANABE M. YOSHIKAWA 《等离子体科学和技术》2006,8(1):87-90
Target plasmas, on which the formation of the electrostatic potentials and the improvement of the confinement are studied, are produced with ICRF in the GAMMA 10 tandem mirror. The ion temperature of more than 10 keV has been achieved in relatively low density plasmas. When the strong ICRF heating is applied, it is observed that the high frequency and the low frequency fluctuations are excited and suppress the increase of the plasma parameters. Recently, a new high power gyrotron system has been constructed and the ECRH power in plug extends up to 370 kW. The improvement of the confinement due to the formation of the potential in the axial direction and the strong radial electric field shear has been observed. 相似文献
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日建设计东京总部大楼是采用钢框架 被动耗能体系的中高层智能办公大楼,竣工于2003年3月。其被动耗能体系由受压失稳制约型制振支撑(低屈服点100MPa钢)和粘滞型制振墙构成,且大楼里安装了可以持续测量地震运动的地震观测系统。本文介绍了2003年4月到2005年3月观测到的43条地震波的地震运动特性的分析结果、地基影响以及结构反应特性。这43条地震波分为两组:A组为中震,震中靠近建筑;B组为大震,震中远离建筑。作者得出结论,对于周期不大于1s的分量来说地基放大特性和输入损失比较显著。 相似文献
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Structure of Inclusion Complexes of Cyclodextrins with Triglyceride at Vegetable Oil/Water Interface
K.AZUKO SHIMADA K.IMIKO KAWANO J.UNKO ISHII T.AKASHI NAKAMURA 《Journal of food science》1992,57(3):655-656
The interfacial tension of vegetable oil (soybean oil or coconut oil)/ water interface decreased with the increase of cyclodextrin (CD) concentration. The interfacial excess and interfacial area were calculated from the Gibbs’ adsorption equation. The average number of CD molecules including a fatty acid residue of soybean oil at the interface was estimated at 2.4 for each of α-CD and β-CD. The average number of CD molecules complexed with a fatty acid residue of coconut oil was 1.8 for α-CD and 1.7 for β-CD. These results suggested that the CD molecules formed the inclusion complex with the triglyceride according to the chain length of fatty acid residue at the interface. 相似文献
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YOSHIRO MASADA KEIJI HASHIMOTO TAKEHISA INOUE MARIO SUZUKI 《Journal of food science》1971,36(6):858-860
SUMMARY— The pungent principles of Capsicum annuum includes at least five closely related compounds . Four of these pungent compounds-capsaicin, dihydrocapsaicin, nordihydrocapsaicin and homodihydrocapsaicin-were separated by gas chromatography with a 3% SE-30 column and identified by combined gas chromatography-mass spectrometry. Separation of these compounds into oleoresin capsicum by gas chromatography is also reported. 相似文献
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本文研究用还原法溶解毛发,回收具有再生成双硫键效力的可溶性蛋白质,建立一个衡量制革用动物毛发的标准。 相似文献