查询词典 ultra-low frequency

The outlines of thesis are as follows: In order to solve the problems that noises such as corona can not be removed by routine electrical measurement methods and the signal of PD generated from the GIS can be picked up effectively, the transmission character of electromagnetic wave generated by PD in GIS is studied. The ultra high frequency band of the signal is chosen to solve the problem.

主要工作如下：针对GIS局部放电在线检测技术中既要避开常规电气方法难以排除的电晕等干扰，又要有利于接收信号的关键问题，研究了GIS内的局部放电信号发出的电磁波的传输特性，选择超高频段信号为接收信号。

An online monitoring system of partial discharge in GIS based on ultra high frequency method is introduced in this paper,it can be real-time monitoring the discharge of fixed particles, unbound particles, floating electrode and insulation defects, accurately reflecting the state of 1000kV GIS.

介绍一种基于UHF方法的GIS局放在线监测系统，可以实现对1000kV GIS内部固定粒子、自由粒子、浮动电极及绝缘缺陷放电情况的实时监测，准确反映1000kV GIS的状态，给1000kV GIS的运行维护工作带来很大帮助。

According to different detection principles and chosen sensors,current methods for XLPE power cable partial discharge detection are classified into acoustic emission,capacitive coupling,inductive coupling,ultra high frequency and directional coupling,etc.

综述了XLPE电力电缆局部放电检测技术的研究现状，重点介绍了用于电缆的各种局部放电检测技术和定位方法。

It is found in field detection that ultra high frequency signals can diffract from the joint of transformer. The feasibility of using external UHF sensor for detecting partial discharge activities is discussed, and the external propagation characteristic of UHF electromagnetic wave is investigated via the lab experiment.

针对变压器箱体的接缝处可以衍射出局部放电特高频电磁波信号的现象，在分析变压器箱体接缝对局部放电特高频电磁波传播影响的基础上，探讨了接收天线外部检测特高频信号的可行性，并通过实验研究了局部放电特高频电磁波的外传播特性，通过对信号进行小波包分析，比较了外部接收和内部接收信号的差异。

The principle of partial discharge detection of gas insulation switchgear with ultra high frequency is discussed.A 220 kV GIS bus bar cavity is adopted as a test object to design and simulate four typical defect models in GIS.The PD signals produced by the four models are obtained via the PD detection system,which is developed by the authors on the basis of the narrow band UHF method.

为了提高GIS运行的可靠性，笔者简要说明了超高频法检测GIS局部放电的原理，并在实验室以一段220 kV电压等级的GIS母线为试验对象，设计和模拟了GIS中典型的4种局部放电模型，并使用自主研发的超高频窄带检测系统对其局部放电信号进行检测。

However,this may causes analysis errors for ultra-high frequency transducers.

但这种处理方法在分析超高频换能器时会带来较大的分析误差。

A multi-resonant DC/DC converter, which is very fit for ultra-high frequency applications is analyzed.

分析了一种非常适合工作在超高频下的多谐振DC/DC变换器。

Due to complex internal structure of a transformer,the propagation characteristics of the partial discharge ultra-high frequency signal are very complicated.

受变压器内部复杂结构的影响，局部放电超高频信号在变压器内部的传播特性非常复杂。

Due to the development of electronic computers, Analysis of the structure can be simplified plane over to a more precise calculation of three-dimensional space. For ultra-high frequency static set the structure, not only can greatly accelerate the speed, and may perform complex structure of the optimal design.

由于电子计算机的发展，结构的受力分析可有简化的平面问题过度到较为精确的空间立体计算，对于超静定次数很高的结构，不但能大大加快计算速度，并且可能进行复杂结构的优化设计。

Future research should focus on the analysis of ultra-high frequency data, volatility persistence, unconditional fat-tail distribution, and high dimensional system.

后续研究应该注重对超高频数据分析、波动的持续性、无条件分布的厚尾性及高维系统的分析。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失