Mike Krzyzewski is really a famous coach of Dream Team. She has coached north america men's basketball team for some time, that's clinched numerous medals for his country. Following Londonfl jerseys supplyn Olympic was over, Krzyzewski told The Associated Press that this game will be his final one as national coach, a job he's held for seven years. He had left open the possibility of swomen nfl jerseystaying with the team beyond the London Games, when practice on Saturday said these will be his last Olympics.When asked if he was sure, Krzyzewski didn't hesitate before again saying, "yecheap nfl jerseys wholesales," this will be his last game "If we could win it, then it might be three major championships in a row, i always do not know when that has been done because we haven't usually won http://govoriotkrito.bg/libs/nflcn08.htmthe globe championships," Krzyzewski said. "It becomes an enormous thing for the program." Whatever, he's an awesome coach. His achievement are going to be remembered by the country.cheap nfl jerseys
你的位置:首页 > 新闻动态 > 技术动态

不同环境使用不同型号的真空断路器

2013/11/16 14:20:34      点击:

我们根据断路器的特点来使用不同环境选用的断路器的型号,具体内容如下:   

一、灭弧原理及基本结构
  真空断路器的灭弧原理是在真空泡内触头拉开时,产生电弧,电弧内携带了蒸发的金属气体,这些气体是从触头表面产生的,最后还会冷却在触头表面和封闭罩的内表面。当电流过零点时,原始的真空状态迅速恢复,间隙处的介电强度迅速增加,电路被切断。
  由于采用真空作为灭弧介质,断路器的结构比较简单,整体部件少。

二、可靠性及使用寿命
  真空断路器的真空泡在正常情况下,在整个寿命期内都是密封的,所以可以保证很高的真空度,在断路器操作过后,真空度也不会降低,这就保证了额定电流和额定开断电流值不会降低,有效地提高了断路器的可靠性。
  在产生电弧时,由于会产生金属气体,断路器的触头会有一些磨损,但是这种磨损程度很小,完全在可控范围内,在要求的机械操作10000次寿命期内是彻底免维护的。因此,可以说真空断路器正常的使用寿命可以达到几百年,超过ANSI,IEC标准要求的使用寿命。

  三、对环境的影响
  真空断路器产生的是少量的纯金属气体,Cu,Cr气体,而且基本被触头重新捕捉,即使在最恶劣的情况下,即真空泡破裂,释放出的气体对环境的影响也小得可以忽略不计。
  良好的灭弧介质和触头材料使得真空断路器能满足IEEE要求的暂态恢复电压速率。
 

      四、总结:对真空断路器的技术特点进行总结,并对其用作发电机出口断路器的情况进行分析,认为其具有高可靠性、免维护、长寿命、经济性好等优点,技术上能够满足作为发电机出口断路器的要求,值得推广用作发电机出口断路器。

  技术和材料的改进使真空断路器用作发电机出口断路器的主要障碍逐步被消除,而同时使它的结构简单、可靠性高、维护量小及寿命长等优点日益显现出来。

奇米影视7777狠狠狠狠影视