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超导线圈交流损耗的测量,能为研究超导线圈交流损耗提供重要方法,并对应用中超导线圈的优化提供重要依据。通过测量电流电压得到功率、再对时间积分的方法,来计算交流损耗,实验中可采用电容补偿降低电源功率负荷,电感补偿降低采集信号噪音,调整采样周期进一步提高采集效率和信噪比等方法来进行。将超导单带在88 Hz及小线圈在90 Hz的实验结果,与理论公式、经典锁相放大器测试结果对比,实验结果中交流损耗从小电流到大电流的差别为17%~1%,证明用该方法测量超导线圈交流损耗,准确、合理。 相似文献
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本文研究了处于混合态非均匀磁化的高温超导椭球在线性响应区的交流磁化率,给出了不同离心率的非均匀磁化椭球在直流磁场和小交流磁场中的交流磁化率的解析解析阐明了样品几何形状(退磁因子)对交流磁化率的影响文中研究了处于超地椭球的交流磁化率。 相似文献
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今天,由于交流感应电动机的构造简单、价格便宜、使用方便、保护容易等优点,因此它在工业上获得了极其广泛的应用。作为一个高中毕业生,是应该懂得有关交流感应电动机的基础知识的。我们在讲授“三相交流电”的基础上,又进行对交流感应电动机作了补充讲授。尽管感应电动机的构造比直流电动机简 相似文献
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C ICC超导体是大型低温超导磁体的首选导体,它运行在大电流和磁场快速变化的环境中,磁通进出超导体以及外界磁场的变化会产生交流损耗,而交流损耗对C ICC超导体稳定性运行有很大的影响,这样开展C ICC超导体交流损耗的研究就显得非常重要。因此,文中针对C ICC导体运行条件和几何结构,提出交流损耗数字模拟的想法,并将数字模拟结果与工程计算值进行了比较和分析,二者基本吻合。 相似文献
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YBCO线圈的交流损耗直接关系到YBCO设备的运行成本及稳定性。实现对YBCO线圈交流损耗的快速、准确测量,对于开展YBCO涂层导体的应用研究具有重要的意义。文中采用电测量法,在77K、零场和不同频率条件下,对YBCO线圈通以不同运行电流时产生的交流传输损耗进行测量。构建了YBCO线圈交流损耗的数值计算模型,对YBCO线圈交流损耗进行理论研究,最后将实验数据与理论计算结果进行比较,两者结果基本一致。可以发现,YBCO线圈在频率低于75Hz时,交流传输损耗随频率的增大而减小,当频率从75Hz增加到195Hz时,交流传输损耗随频率的增大而增加。 相似文献
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ZENG Jianer RAO Jun KANG Zhihua LI Bo WANG Mingwei LU Zhihong ZHOU Jun HUANG Mei FENG Kun 《核工业西南物理研究院年报(英文版)》2006,(1):76-78
In the last year, ECRH system has been built in the HL-2A and the testing of gyrotron is also finished. In the project testing, one of the problems is current-peak occurring in the anode circuit of gyrotron. The current-peak is much larger than that of the value set in protection circuit. The frequent current-peak frequently occurring in the rising of anode-voltage often caused the protection circuit to mistaken trigger. The mistaken triggering often halted the normal gyrotron-testing. A set of equations of anode circuit are derived for analysis the phenomena of the current-peak. The calculation based on the deduced formula shows that value of the current-peak strongly depends on the inductance L, capacitance C and the ramp-time of anode voltage in the anode circuit. The conductance L and capacitance C are the characteristic inductance and capacitance of the cable that is used for anode HV power supply. The numerical calculation is exactly consistent with waveform of the current peak recorded by oscillograph, that means the derived formula are correct. In order to decrease the value of the current-peak, we should decrease capacitance C, and increase inductance L and ramp-time of anode voltage. 相似文献
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RC电路是最基本的一阶动态电路,在电路中由于受电阻和电容元件参数的限制,电路的时间常数通常很小,测量过程难于实现.本文对RC电路进行了改进型设计,提高了RC电路时间常数值,使测量过程得以实现。 相似文献
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The measurement circuit of electrical capacitance tomography (ECT) system mainly includes CMOS switches, C/V conversion circuit and Data processing circuit. In order to improve the image reconstruction quality, conversion circuit is very necessary to the small capacitance measurement circuit. A charge/discharge measurement circuit is one of the most suitable for the C/V conversion circuit in ECT. The stray capacitance between the measurement electrodes and earth can be large and have an effect on the capacitance measurement. This paper analyzes this effect, taking into account the ON-resistance of the COMS switch, the unit gain frequency of op-amp, and gain error in the measurement circuit. Finally, it is shown that if the range of stray capacitance is 150 ± 60 pF, overall error would be estimated. Comparing the effects of the circuit parameters, this charge/discharge-based capacitance is effectively stray-immune. It is a more efficient analysis to C/V circuit in ECT and offers a great benefit to information processing. 相似文献
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提出一个新的五阶超混沌电路. 该电路由三个线性电感、两个线性电容、一个线性负电阻和二个非线性元件组成,并具有π形的电路结构. 其主要特征是,利用非线性元件的作用来切换电路中的时间常数,使其电压和电流发生急剧变化. 利用负电阻可满足电路局部发散的条件,并且这种电压和电流的急剧变化以及局部发散是该电路产生混沌与超混沌的两个前提条件. 分岔和李雅普诺夫指数计算结果表明,随着分岔参数的改变,电路的振荡机理由周期态演变为混沌态,再由混沌态演变为超混沌态. 设计了五阶超混沌电路,给出了硬件实验结果.
关键词:
超混沌电路
超混沌吸引子
电路实验 相似文献
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The voltage-current relationship and equivalent circuit implementation of parallel flux-controlled memristive circuits
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A flux-controlled memristor characterized by smooth cubic nonlinearity is taken as an example, upon which the voltage-current relationships (VCRs) between two parallel memristive circuits - a parallel memristor and capacitor circuit (the parallel MC circuit), and a parallel memristor and inductor circuit (the parallel ML circuit) - are investigated. The results indicate that the VCR between these two parallel memristive circuits is closely related to the circuit parameters, and the frequency and amplitude of the sinusoidal voltage stimulus. An equivalent circuit model of the memristor is built, upon which the circuit simulations and exper/mental measurements of both the parallel MC circuit and the parallel ML circuit are performed, and the results verify the theoretical analysis results. 相似文献