110kV降压变电所电气部分设计英文文献(共7页).doc
![资源得分’ title=](/images/score_1.gif)
![资源得分’ title=](/images/score_1.gif)
![资源得分’ title=](/images/score_1.gif)
![资源得分’ title=](/images/score_1.gif)
![资源得分’ title=](/images/score_05.gif)
《110kV降压变电所电气部分设计英文文献(共7页).doc》由会员分享,可在线阅读,更多相关《110kV降压变电所电气部分设计英文文献(共7页).doc(7页珍藏版)》请在得力文库 - 分享文档赚钱的网站上搜索。
1、精选优质文档-倾情为你奉上英文文献Cirtcuit BreakersA circuit breaker is mechanical switching device capable of making,and breaking currents under normal circuit conditions and also making.carring for a specified time ,and mediujm in which circuit interruption is performed may be designated by a suitable prefix, for
2、example,air-blastcircuit breaker,oil circuit breaker.The circuit breakers currently in use can be dlassified into the following categories according to the arc-quenching principles:air swetches oel ciryit breakers,minmum-oil circuit breakers,air-blast circuit breakers,the magenetic air circuit break
3、ers,minimum-oil circuit breakers,aer-blast circuit breakers,the by voltage,insulation levelcurrent,interrupting capabilities,transient recovery coltage,interrupting tiome,and trip delay.The nameplate on a circuit breaker usually indicates:.The maximum steady-state current it can carry, 2. The maximu
4、m interrupting current,3. The maximum line voltage,4.The interrupting time in cycles, The interrupting time in may last form 3 to 8 cycles on a 60 Hz system. To interrubt large currents quickly, we have to ensure rapid cooling. High-speed interruption lunits the damage transmission lines and equipme
5、nt and, equally important,it helps to mainmain the stability of the system whenever a contingency occurs. The main parts of a circuit breaker are usually:arc-quenching chamber (or interrupter with moving and fixed contacts) operating mechanism and supporting structures. Air Switches-With increasing
6、currents and voltages, spring-action driving mechanisms were developed to reduce contact buring by faster-opening operation.Later,main contacts were fitted with arcing contacts of special material and shape,which opend after and closed before the main contacts.Further improvements of the air switch
7、were the bursh-type contact with a wiping and cleaning function,the insulating barrier leading to arc chutes,and blowout coils with excellent arc-extinguishing properties.These features,as well as the horn gap contact,are still in use in low voltage as and de breakers. Oil Circuit Breaker Around 190
8、0, in order to cope with the new requirement for “interrupting capacity”,AC switches were immersed in a tank of oil. Is very effective in quenching the arc and establishing the open break after current zero.Deion grids,oil-blast features,pressure-tight joints and vents,new operating mechanisims,and
9、multiple interrupter were introucedover several decades to make the oil circuit breaker a reliable apparatus for system voltage up to 362Kv.Types and Construction of TransformerA transformer is a device that alternating current electric energy at one voltage level into alternating current electric e
10、nergy at another voltage level through the action of a magnetic field.It consists of two or more coils wire wrapped around a common ferromagnetic core.These coils are (usually)not directly connected. The only connection between the coils is the common magnectic flux presen within the core.One of the
11、 transformer windings is connected to a source of ac electric power,and the second(and perhaps third) transformer winding supplies electric power to loads. the transformer winding connected to the power souce is called the primary winding or input winding.and the winding connected to the loads is ca
12、lled the secondary winding or input winding.If there is a third winding on the transformer,it is called the tertiary winding.Power transformer are constructed on one of two types of cores.one type of construction consists of a simple rectangular laminated piece of steel with the transformer windings
13、 wrapped around two sides of the rectangle.This type of construction is know as coreform .The other type consists of three-legged laminated core with the windings wrapped around the center leg .This type of construction is know as shell form.In either case,the core is constructed of thin laminations
14、 electrically isolated form each other in order in order to reduce eddy currents to a minimum.The primary and secondary windings in a physical transformer are wrapped one on top of the other with the low-voltage winding innermost.Such an arrangement severs two purposes: 1.It simplifies the problem o
15、f insulating the high- voltage winding from the core.2.It results in much less leakage flux than would be the two windings were separated by a distance on the core.Power transformer are given a variety of different names, depending on their use in power systems.A transformer connected to the output
16、of a generator and used to step its voltage up to transformer levels is sometimes called unit transformer. The transformer ai the other end of the transformer line,which steps the voltage down from transmission levels to distribution levels,is called a substation transformer.Finally,the transformer
17、that takes the distribution voltage and steps is down to the final voltage ai which the power is actually used is called a distribution transformer.All these devices are essentially the same-the only difference among them is their intended use.In addition to the various power transformer, two specia
18、l-purpose transformers are used with electric machinery and power systems.The first of these special transformers is a device specially designed to sample a high voltage and produce a low secondary voltage directly proportional to it.Such a transformer is called a potential transformer.A power trans
19、former also produces a secondary voltage directly proportional to its primary voltage;the difference between a potential transformer and a power transformer is that the potential transformer is designed to handle only a very small current.The second type of special transformer is a device designed t
20、o provide a secondary current.much smaller than but directly proportional to its primary current.This device is called a current transformer.Lingting protectionThe thunder and lightning protects to connect the ground; Connect the ground to avoid the thunder the most important link of the technique,
21、ignore is a shot thunder, respond the thunder of the thunder or other form, and avoid the thunder work most all of send into the earth the thunder electric current. Store the thunder energy to behave the type to build the , current technology to still reach to not arrive, and therefore have no the r
22、easonable but good connect the ground equip to is impossible to speak about to defend the thunder.Therefore say the design, the construction is very high standard to connect the ground system is a heavy inside that defend thunders work it heavy. High electric potential that For long time, people hav
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- 110 kV 降压 变电所 电气 部分 设计 英文 文献
![提示](https://www.deliwenku.com/images/bang_tan.gif)
限制150内