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电磁阻尼器气隙磁场的磁感应强度是影响阻尼力矩大小的重要因素。基于有限元电磁场分析软件MagNet建立三维仿真模型,在0~5 000 r/min转速范围内进行三维瞬态运动仿真,通过改变磁钢材料和磁极对数,研究了气隙磁通密度变化对力矩特性的影响。仿真获知电磁阻尼器阻尼力矩与气隙磁密基波幅值的平方成正比关系。 相似文献
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针对空间对接机构中使用的空心转子杯式电磁阻尼器的工作原理以及结构特点,设计了一种混合励磁式的电磁阻尼器,并对其阻尼力矩计算方法进行了研究,建立了相应的数学模型。在MagNet软件中建立混合励磁式电磁阻尼器的二维模型,对杯形转子电磁阻尼器的阻尼力矩进行有限元分析,主要分析了阻尼器的几个关键参数与阻尼力矩的关系以及不同电励磁条件下阻尼力矩与转速的关系,为电磁阻尼器的设计与研究提供了理论基础。 相似文献
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电磁阻尼器是一种利用涡流阻尼作用使运动系统的震荡快速衰减的装置。在一些工业场合中,系统往往需要多自由度的阻尼力,传统方法是采用多个单自由度阻尼器进行组合,但是存在机械结构与系统构成复杂的缺点。该文提出一种平面电磁阻尼器,该阻尼器能够利用一个运动部件同时提供两正交方向的电磁阻尼力,具有结构简单、安全可靠等优点,可应用在光刻机工件台等需要两自由度快速稳定定位的场合中。介绍了平面电磁阻尼器的结构和工作原理,利用磁荷法和镜像法对永磁阵列的三维空间磁场进行解析,推导出电磁阻尼力的解析表达式。利用有限元对影响电磁阻尼力的尺寸参数进行分析,得到电磁阻尼力及阻尼系数的变化规律。实验结果与理论计算基本一致,验证了理论分析的正确性。 相似文献
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针对常规磁流变阻尼器功能单一且能量采集效率低下的不足,提出并设计了一种集阻尼力可控、位移自感应和振动能量采集多功能于一体的位移自感应振动能量采集型磁流变阻尼器。介绍了所设计的阻尼器工作原理及位移自感应工作特性。采用ANSYS有限元仿真软件对处于不同工作位置的位移自感应装置进行电磁耦合仿真,得到自感应电压随活塞头相对位置的分布关系。加工制造出样机并搭建实验测试系统,测试分析了该磁流变阻尼器的动态位移自感应性能。测试结果表明:自感应电压幅值随着位移激励幅值的增大而线性增大,且其线性灵敏度达到54.37 mV/mm。 相似文献
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Magnetic and conductive shielding are the alternative choices for air‐core pulsed alternators (air‐core CPAs) in electromagnetic railgun systems. Because of the absence of ferromagnetic materials in the air‐core alternators, the flux density inside can be 3–5 T. Electromagnetic shielding is needed to protect the surrounding electronic devices and humans from exposure to high oscillating magnetic fields. Electromagnetic shielding changes the distribution of the magnetic field and the corresponding winding inductance, as well as the output performance of the powering the railgun. This paper mainly concentrates on a GW‐scale, four‐phase air‐core CPA‐based railgun system. The magnetic and conductive shielding are adopted correspondingly. The effectiveness of shielding and electric performance are investigated in detail. Using the co‐simulation method, an instructive comparison is made between the magnetic shield and the conductive shield, which is meaningful to the design of the electromagnetic shielding of air‐core CPAs for railgun systems. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
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用有限元法计算稀土永磁电机的气隙磁场,并用傅立叶变换代替传统的傅立叶级数进行波形分析,利用麦克斯韦应力张量法和磁通法计算出电磁转矩.得到较好的结果。 相似文献
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Yutaka Takahashi Keiji Yamamoto Masahiro Nishikawa 《Electrical Engineering in Japan》2006,154(4):68-74
The engine essentially consists of a rotor made of temperature‐sensitive magnetic material and permanent magnets. When an object made of this material has a temperature distribution in the magnetic field, the force is generated in the direction from the low‐temperature side to the high‐temperature side by magnetic pressure. This paper describes the fundamental performance of the triple magnetic circuit type thermomagnetic engine. A triple magnetic circuit type engine with water‐cooling system has ben designed. The performance characteristics such as power, resistance loss, and the relation between the temperature of the rotor and the rotation speed have been measured, and compared with the characteristics of a single magnetic circuit type engine. The net power is a maximum value of 3.7 W at a rotation speed of 0.4 rps. The power of the triple magnetic circuit type engine per unit magnetic circuit is about 4 times larger than that of the single magnetic circuit type engine. The resistance loss is 1.7 W at the maximum power point. The total power is 5.4 W. Electromagnetic braking loss is about 25% of the total power. The rate of electromagnetic braking loss to the total power increases with the rotation speed. The disk type rotor with small electromagnetic braking loss has been analyzed. Electromagnetic braking loss of the disk type engine becomes about 95% smaller than that of the cylinder type engine. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 154(4): 68–74, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20127 相似文献
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电磁污染属于科学研究领域很难迅速给出答案的问题之一。“电磁污染”这个名称直截了当的暗示着威胁和恐惧。对健康的影响造成的不安全性,一般认为应当通过环境保护法预防原则来规避。很少有人注意的是,通过适当的电气设备以及家中的简单措施也可以降低电磁场的强度。 相似文献
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Electromagnetic shielding properties of soft magnetic metal and ferrite composites for application to suppress noise in a radio frequency range 总被引:1,自引:0,他引:1
Yong Woon Yun Sang Woo Kim Gwang Yoon Kim Yoon Bae Kim Yeo Chun Yun Kyung Sup Lee 《Journal of Electroceramics》2006,17(2-4):467-469
Electromagnetic shielding properties of soft magnetic metal alloy (Fe-Al-Si) flakes and Ni-Zn ferrite composites for effective
suppression of broadband and high frequency noise were investigated. In the soft magnetic composites, the maxima of reflection
loss were shifted to high frequency with increase in content of Ni-Zn ferrite. The composites with content of 50 and 70% ferrite
exhibited broadband absorptive characteristics. The broadband character- istics might be caused by the extended resonance
due to an overlap between imaginary permeability and permittivity of the two composites over the frequency range from 2 to
10 GHz. 相似文献
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直线磁场调制电机由于材料成本受行程长度影响较小,适合于长行程应用场合。为获得更好的推力特性,本文从理论研究入手,分析了直线磁场调制电机推力的解析公式,进而确定气隙磁密谐波含量影响推力特性。为了提高气隙磁密的正弦度,电机采用Halbach永磁阵列,相比于传统法向充磁直线磁场调制电机平均推力提高18%,但推力波动率也增大了3.4%。为了尽量降低推力波动,利用有限元法对Halbach永磁体结构、电枢齿靴宽度、调磁块的尺寸和形状等结构参数进行参数化分析与改进设计。最终平均推力为783N,相比于传统法向直线磁场调制电机平均推力提高了44.5%,推力波动率从16.1%降低到8.3%。 相似文献
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An electromagnetic model of a multiphase inductive furnace is considered in the early stages of smelting. The furnace is charged with a set of metallic pieces that are not electrically connected to one another. They may or may not have magnetic properties, depending on the temperature. Electromagnetic processes in furnaces with such a charge are investigated in the case of single-phase and multiphase power supply to the inductor. 相似文献
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磁体外部片状均匀磁场区的构建 总被引:4,自引:3,他引:4
在磁体外部构建片状均匀磁场区域,是磁体设计所面临的一个全新问题。文中提出了一种混合逆数值算法,以探索这种设计的可行性。混合逆数值算法是一种两步算法,包含直接矩阵反演求逆和二次规划两个步骤。文中对该数值算法进行了详细的描述,并用它成功地找到一种多磁块组合的单边永磁磁体结构。经通用有限元计算软件仿真和对磁体模型的测量表明,这种磁体结构能够较好地在磁体外部一侧构建片状均匀磁场区。用单边永磁磁体在磁体外部构建片状均匀磁场区的实现,为开展单边均匀场常规磁共振成像系统研制等科学研究打下了坚实的基础。 相似文献