雷击

Unfortunately,the surge protection devices are occasionally faulty because of the protection indeterminateness due to the design and installation of SPD.We discussed the random characteristic of lightning strike,the breakdown time delay and jitter of SPD,multi-stages protection blind zone,the reflection oscillation of lightning wave between loads and SPD's,and proved the indeterminateness o...

由于SPD设计和施工带有多方面的不确定性，使被保护系统可能出现故障，导致SPD保护失效，因此从雷击特性的随机性、组成SPD元器件的击穿时延和分散性、多级保护盲区、雷电波在负载与SPD之间的反射振荡特性等方面进行了分析探讨，最终得出了SPD保护不确定性的必然性。

The influence of the line arrester on the lightning withstand level of 35kV transmission lines was simulated and calculated by electromagnetic transient software ATP-EMTP. The results show that the joining of line arrester can obviously improve the lightning withstand level of 35kV transmission lines, and is especially effective when the lightning directly strikes the conductor.

计算结果表明，在"易击段"架设线路避雷器后，可明显提高35kV输电线路的耐雷水平，尤其雷直击导线时，线路避雷器的作用效果更加明显；雷击杆塔塔顶时，杆塔接地电阻是影响35kV输电线路耐雷水平的重要因素。

Considering some factors,including the different operation mode and lightning strike location,also calculates and analyzes the infection of the impulse grounding resistance of transmission tower,the lightning arrester s arranging and parameter for protection effect.

采用PSCAD/EMTDC程序计算分析了西北电网兰州东-银川东输变电工程750kV银川东变电站330kV线路雷电侵入波过电压保护，考虑了不同运行方式、不同雷击点的情况，还计算分析了杆塔冲击接地电阻、避雷器的布置及参数对保护效果的影响。

It can reduce the numbers of lightning accidents after sing of the overhead insulating conductor, but the accident of overhead insulating conductor broken by lightning stroke still happens from time to time.

采用架空绝缘导线后，可以大大降低雷害事故发生次数，但是在实际运行中架空绝缘导线雷击断线的事故却时有发生。

It is not reasonable that striking distances of lightning leader to phase conductor, ground line and the ground are equal in classical electric geometry method.

针对经典电气几何模型认为雷电先导对导线、避雷线、大地三者之间击距相等的不合理问题，提出了用击距系数来描述雷电先导对导线与大地击穿强度的差别；依据长间隙放电与雷击放电的相似性，开展了棒-板间隙实验以得到击中目的物概率为50%时雷电先导与地面、导线之间的位置关系。

The accidents statistics from 2000 to 2003 are analyzed in this paper.Based on the tradition lightning conductor,ATPsoftware is used to stimulate the operation of zinc oxide surge arresters,and good effect is taken according to the data of the stimulation.Our plan is to install zinc oxide surge arresters on the power grid and the pole where there are easily destroyed by the lightning.The work from July 2004 to May 2005 is finished.

对2000～2003年来雷击事故进行了统计分析，在传统避雷线、杆塔接地装置防雷设施基础上，采用ATP软件对安装线路氧化锌避雷器进行仿真计算，依据仿真结果，确定了在架空线路易击段、易击杆塔、特殊地形地貌杆塔安装线路型氧化锌避雷器方案，并从2004年7月至2005年5月在35kV、110kV架空线路上安装了线路型氧化锌避雷器。

Using this knowledge, he invented the lightning rod which today protects millions of buildings from lightening.

利用这一知识，富兰克林发明了避雷针，才使今天数以百万计的建筑物免遭雷击。

Using this knowledge,he invented the lightning rod which today protects millions of buildings from lightning.

利用这一知识，富兰克林发明了避雷针，才使得今天数以百计的建筑物免遭雷击。

Using this knowledge, Franklin invented the lightning rod which today protects millions of buildings from lightning.

利用这一知识，富兰克林发明了避雷针，才使得今天数以百万计的建筑物免遭来雷击。

While you are much safer inside than out,lightning can strike you even in the home.

你在室内比在室外安全一些，但即使你在家里你也会被雷击。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。