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根据多年来的实践经验,阐明了天馈线电压驻波比劣化对数微波电路的影响,包括回波干扰和收发干扰。并比较了测量天馈线电压驻波比的几种不同方法。 相似文献
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微波通信在电力系统的安全生产和调度运行中发挥着重要的作用,但由于微波传播是直线传播,通道一旦受阻,信号就会受到影响,甚至通信中断。这种情况随着城市高层建筑的迅速发展已经屡有发生,因此做好微波电路空中走廊的通道保护工作已日益重要。微波站的建设单位应向规划局申请微波通道保护,内容应包括微波通道保护的宽度,位于微波通道上的建筑物的允许高度,以及两端微波站天线的精确座标等。得到规划局的批准以后,此条微波通道即已得到保护,并会标示在城建规划图上。下面就微波通道保护的几个要素作进一步讨论。1微波通道保护的宽… 相似文献
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本文主要对微波通信中的数字电路信号压缩技术进行了简要介绍,并对其在安徽省电力通信中的应用前景作出了分析展望。 相似文献
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介绍了微波通信站使用的天馈线电缆转移阻抗的计算及测量结果,并估算了不同雷击电流下天馈线电缆可能引入机房的干扰电压值。 相似文献
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Massimiliano Simeoni 《International Journal of Numerical Modelling》2005,18(3):221-226
The explicit expressions of modal coupling coefficients at planar waveguide junctions are discussed. The coupling coefficients are expressed in terms of projections of the modes on the modal spectrum of a fictitious rectangular waveguide located at the junction plane. The proposed formulation results in an efficient implementation of the modal based analysis of waveguide junctions. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
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R. S. Chen D. X. Wang Edward K. N. Yung 《International Journal of Numerical Modelling》2003,16(4):367-385
A novel numerical de‐embedding scheme called the short‐open calibration (SOC) technique, in conjunction with the vector finite element method (FEM), has been developed to characterize two‐port network of arbitrarily shaped, three‐dimensional discontinuities in microwave circuits. This SOC technique is effectively implemented into the FEM for boundary truncation of the unbounded circuit structures. In such a manner, fast convergence of iterative solver for large‐sparse linear matrix equations from FEM is achieved. The SOC technique is used to remove parasitic effects brought by the approximation of the impressed voltage source and also the problem of resulting consistency between the two‐ and three‐dimensional simulations. Scattering parameters of discontinuous sections are constructed from the definition of port voltages and currents. Numerical solutions are well compared with those published in the available literatures. It is demonstrated that the features of the SOC technique are advantageous when combined with FEM for electromagnetic problems. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
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电能表是电能计量装置中最基本的组件,通过对感应式电能表负荷误差特性的分析,阐述了电能表对配网线损的影响,提出了加强计量电能表的管理措施,以降低配网线损。 相似文献
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在配电网中,配电变压器三相不平衡运行状态普遍存在。三相不平衡会使配电变压器产生附加损耗,导致变压器局部过热,从而对变压器的绝缘寿命、带负荷能力产生很大影响。文章对常用的Dyn11和Yyn0联结方式的配电变压器建立了等效电路模型,研究其在三相不平衡状态下的损耗情况。仿真及试验结果表明,三相不平衡使变压器的损耗大幅增加,且随不平衡度的增加呈二次函数增长,不平衡度为50%时变压器损耗将增加一倍。为了保证变压器的运行安全及运行寿命,在不平衡情况下运行时,需要降低其负载率。 相似文献
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建立了锂电池充放电模型,并在Matlab上形成锂电池模型库,改变关键参数,分析锂电池中各参数对充放电曲线的影响,通过调整锂电池模型中的关键参数提高模型精度。最后,以天康TKLD-48 V/52 Ah系列锂电池实际充放电数据为例,将仿真曲线与实际充放电曲线对比,计算出模型的绝对误差小于3%,符合需求。 相似文献
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A classical eigenvalue mode‐spectrum analysis of waveguides with multi‐ridged cross sections is presented and applied to the design of narrowband waveguide components in rectangular and circular waveguide technology. Modifications of the modes of the empty waveguide enclosures are used as expansion functions and lead to a classical, real and symmetric eigenvalue problem. A simple yet efficient constraint function is introduced to satisfy boundary conditions for TM modes. The number and locations of ridges positioned in a regular rectangular or circular waveguide enclosure is arbitrary. Measurements and comparisons with results from existing full‐wave modeling tools and commercially available field solvers verify the correctness and flexibility of the approach. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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温度变化对应变测量的误差有很大的影响,特别是大规模应变测量广泛采用的1/4桥,因无法进行桥路温度补偿,受温度变化的影响更加显著。如果对每个通道使用半桥温度补偿,则操作复杂,成本高,效率低,所以有必要分析温度变化对1/4桥路测量误差的影响。通过分析应变测量时普通应变片和温度自补偿应变片的热输出原理,以及导线和应变采集器受温度的影响,最终给出在多通道采集系统上使用BE系列普通应变片和温度自补偿应变片时,整个采集系统在温度影响下的测量误差,解决了在结构强度试验中温度变化引起的测量系统误差评定问题,并给出不同温度变化范围内满足1%测量误差所需测量应变的理论计算最小值。 相似文献