ge flux than would be the two windings were separated by a distance on t 隔离一定距离比起来，它导致更少的漏通量。 he core. Power transformer are given a variety of different names, depending on th 电力变压器被赋予了很多不同的名字， 取决于它们在 eir use in power systems.Atransformer connected to the output of a gener 当前系统中的作用。 一变压器连接到一个发电机的输出端， ator and used to step its voltage up to transformer levels is sometimes call 并且用于步调它的电压达到变压器值有时被叫做单位变压器。 ed unit transformer. The transformer ai the other end of the transformer li 变压器一个排在另一个后面——将电压从传送值 ne,which steps the voltage down from transmission levls to distribution le 步降到分布值，
vels,is called a substation transformer.Finally,the transformer that takes th 被叫做变电站。 最后，变压器将分布电压和步幅 e distribution voltage and steps is down to the final voltage ai which the p 降到最后的实际使用的电能被叫做发送变压器。
ower is actually used is called a distribution transformer.All these devices 所有这些设备本 are essentially the same-the only difference among them is their intended 质上都是相同的——它们之间唯一不同的是它们的特定用途。 use. In addition to the various power transformer, two special-purpose trans 除了各种电力变压器 两个专用变压器使用电 formers are used with electric machinery and power systems.The first of t 动机械和电力系统 这些特殊 hese special transformers is a device specially designed to sample a high 变压器中的第一个是一个专门简化高电压产生较低的二次电压而设voltage and produce a low secondary voltage directly proportional to it.S 计的装置
uch a transformer is called a potential transformer.A power transformer al 例如一个变压器叫做电压互感器 一个电力变压器也产 so produces a secondary voltage directly proportional to its primary volta 生二次电压直接与它的初级电压成正比
ge;the difference between a potential transformer and a power transforme 之间差异的一个潜在功率变压器和一个变压器，是潜在的变压器 r is that the potential transformer is designed to handle only a very small c 是设计来处理只有一个很电流。
urrent.The second type of special transformer is a device designed to prov 在第二种类型的变压器是一个特殊装置设计为提供一个二次侧 ide a secondary current.much smaller than but directly proportional to its 电流。 多小但比比例对其直接初级电流。 primary current.This device is called a current transformer. 这个装置叫做电流互感器
Lingting protection 防雷保护
The thunder and lightning protects to connect the ground; Connect the gr 雷电保护接地是避雷技术最重要的环节， 不管是直击雷、 ound to avoid the thunder the most important link of the technique, ignore 感应雷或其他形式的雷， 避 is a shot thunder, respond the thunder of the thunder or other form, and a 雷 工作的最终都是把雷电流送入大地。
void 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 t 储存雷能量为人类造福， 目前科技 echnology to still reach to not arrive, and therefore have no the reasonabl 还达不到，因此没 有合理而良好的接地装置是不可能谈及防雷的。 e 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 st 所以说设计、施工好高标准的接地系统是 防雷工作 andard to connect the ground system is a heavy inside that defend thunder 的重中之重。
's work it heavy. High electric potential that For long time, people have an 长期以来， 人们有一个错 illusion, and think that connect the ground electric resistance more small 觉， 认为接地电阻越小避雷效果就越好，被保护的对 象就安全。 avoid the thunder result and then more like, quilt object that protect safety. Certainly the electric resistance is more the small is more quick, strike 当然电阻越小散流越快， 雷击的 by lightning to reserve time more short, the risk is more small, electric vo 高电位保留时间越短， 危险性越小，其跨步电 压、 ltage of its stride, get in touch with the the electric voltage produce the m 接触电压产生的机遇也就越小。
achine too the more the ?But, construction that the fulfillment proof of ne 但是，近十几年来的实践证明，
ar and more than ten in the last yearses, with its say that connect the wort 与其说接地电阻值重 要， h importance of ground electric resistance, not equal to say that connect t 不如说接地装置的结构更合 he ground to equip more reasonable, importance electricity equipments, d 理、重要。
emand variety that now's city, there is lots of in a building inside not the c 现在的城市， 在一座建筑物内有许多不同性质的电气设 ongeniality connect the ground device, if avoid the thunder to connect the 备，需要多种接地装置 ， 如避雷接地、电气安全接地、交 ground, electricity the safety to connect the ground, AC power the work t 流电源工作接地、通信及计算机系统接地，
o connect the ground, correspondence and calculator system to connect the ground, according to the fulfillment proof, totally use to connect the gro 根据实践证 明， 共用接地是应用最为广泛的 und is an application most for extensive connect the local type. 接地方式。
That A, the independence connect the ground: As above part for demand 一、 独立接地： 如上面所谈到的需要接 for speak ofing connecting the ground of, all distinguish to independently 地的部分， 都分别独立地建立自己的 establish the own to connect the ground system, and this kind of connect 接 地系统，这种接地方式称为独立接地。
the local type to call the independence to connect the ground. Its advantag 它的好处是 e is each system and can't result in the mutual interference, and this is part 各系统之间不会造成互相干扰，这对通 信系统尤其重要。
icularly important to correspondences systems.But the adoption independ 但网络容易被雷击坏， ence that network easily were strike by lightninged is bad, so besides hav 故除有防爆炸 e to defend to explode the dangerous environment requesting to must wan 要求的危险环境必须要采用独立的 避雷方式外，
t the adoption the independence of avoid the thunder method generally no