1、Transformer 变压器 One of the most valuable apparatus in electric power system is the transformer, for it enables us to utilize different voltage levels across the system for the most economical value. Generation of power at the synchronous machine level is normally at a relatively low voltage， which i
2、s most desirable economically Stepping up of this generated voltage to high voltage， extra-high voltage or even to ultra-high voltage is done through power transformers to suit the power transmission requirement to minimize losses and increase the transmission capacity of the lines This transmission
3、 voltage level is then stepped down in many stages for distribution and utilization purposes 电力系统中的最有价值之一是器具的变压器，它使我们能够利用不同电压等级，整个系统的最经济的值。通常在较低功率在同步计算机级别的一代是 voltage ， which ，是最理想的 economically Stepping 高 voltage， extra 高电压该生成电压或甚至超高电压通过以适应电力传输的要求，尽量减少损失的电力变压器和增加 lines This 输电电压等级的输电量然后走在很多阶段的分布和利用
4、的目的 最有价值的一个装置在电力 系统变压器 ,因为它使我们能够利用不同系统电压水平在最经济的价值。一代的电力水平同步机通常以较低的电压 ,这是最理想的 economically.Stepping 这产生电压高压、超高压甚至是通过高压电源变压器适应电力传动要求减少损 失 ,提高传输容量的lines.This 传输电压水平就下来了许多阶段 ,分配和使用目的。 A transformer is a static device for transferring electric energy from one circuit to another electromagnetically， that
5、is， by induction instead of by conduction Its usual function is to transfer energy between circuits of different voltage A transformer has a magnetic core on which there are two or more windings These windings are insulated from each other and from ground In autotransformers， however， the windings a
6、re connected together The assembly of core and coils is normally insulated and cooled by immersion in mineral oil or other suitable liquid within an enclosing tank Connection to the windings is by means of insulating bushings， usually through the cover. 变压器是一个静态的装置电能量转移到另一个排列从一个电路 ,通过诱导而不是conduction
7、.Its 通常以换乘功 能电路 voltage.A 间能量不同变压器磁芯上有一个有两个或两个以上绕组 windings.These 彼此隔离和 ground.In autotransformers,然而 ,绕组连接组装的核心和线圈手工相结合 ,通常是由沉浸在保温和冷却液矿物油或其他适合在一个附上的tank.Connection 绕组通过绝缘衬套 ,通常是通过封面。 变压器是核心的将电能从一个电路转移到另一个 electromagnetically， that is， by 感应而不是核心的，由 conduction Its 常用函数的静态装置是核心的 不同的 voltage A 变压器电路之间
8、传输能量已磁芯的有两个或更多的 windings These 绕组彼此隔离从 ground In autotransformers， however， the 绕组连接的 together The 大会和是核心的线圈通常是核心的绝缘和冷浸于矿物油中或其他合适的液体内封闭 tank Connection 在绕组绝缘盖通过 bushings， usually 的手段。 The “ratio of transformation” is determined by the relative number of turns in each of he windings This is known as
9、the “turn ratio” and it is the ratio of the no-load voltages When the unit is carrying load, the ratio of the actual voltages is slightly different because of the drop caused by the flow of 1oad current through the impedance of the transformer windings At rated load, this drop is known as the voltag
10、e regulation. The amount of voltage drop varies with the power factor of the output even when the kilovolt-amperes remain constant Practically all power transformers and many distribution transformers have taps in one or more windings for changing the turn ratio Changing the ratio is desirable for t
11、wo reasons to compensate for varying voltage drop in the system and to assure that the transformer operates as nearly as possible at the correct core density For the latter purpose, the taps should be in the winding subject to the voltage variation. De-energized tap changers are used when it is expe
12、cted that the ratio will need to be changed only infrequently, because of load growth or some seasonal change The desired tap is selected by means of a ratio adjuster(no load taps) Load tap changer(LTC)is used when changes in ratio may be frequent or when it is undesirable to de-energize the transfo
13、rmer to change a tap It seldom makes much difference to the user which winding or windings are tapped； therefore， the choice is usually made by the designer on the basis of cost and good design. Both winding current and voltage must be considered when applying LTC equipment High voltage and high cur
14、rent applications require special considerations to arrive at an optimum location for the LTC equipment Step down units usually have LTC in the low-voltage winding and de-energized taps in the high voltage winding 转型的比率 是由他每圈相 对数决定的 windings This 称为 转率 ，这是空载 voltages When 股的比例承载负荷，因为下降 1oad 通过的阻抗变压器
15、 windings At 额定负载电流的流动引起的实际电压的比例略有不同这滴被称为 电压调节 。即使当千伏安培保持所有电源变压器和许多配电变压器有水龙头的一个或多个绕组更改比率是可取的原因有两个补偿系统中变电压降，并向保证变压器操作正确核心 density For，后者的目的在尽可能接近的转 ratio Changing constant Practically 的电压降量随输出的功率因素水龙头应在电压变清盘。切断调压分接开关时预期比例将需要更改只有很少，因为负荷增长的使用或一些季节性的 change The 需要选择了水龙头比调节器 (无负荷水龙头） 的方式时比率的更改可能会频繁 , 而使用
16、 Load 分接开关 （ LTC） 时，是不可取 de-energize 更改很少 tap It 变压器多大差别，用户或其中缠绕或绕组用 tapped；therefore， the 选择通常是由设计器成本和好的设计的基础上作出的。绕组电流和电压必须考虑当应用 LTC equipment High 电压和高当前的应用程序需要特殊的注意事项，到达最佳位置为单位下来 LTC equipment Step 通常会 LTC 中低压绕组和断电丝锥在高电压 winding “比转变”是由相关的圈数他 windings.This 在每个被称为“转比率”以及它是空的比例 voltages.When 单位带负荷、粮经比实际电压下降的略有不同 ,因为造成 1 oad 流动的电流通过阻抗变压器的额定载荷的 windings.At,这滴被称为“电压调节”。电压降的数量随输出的功率因数即使 kilovolt-amperes 保 持不变。 几乎所有开关电源变压器、配电变压器有许多水龙头在一个或多个线圈来改变这一比例将 ratio.Changing 是可取的 ,有两个原因来补偿系统中不同电压降 ,以确保变压器运行正像可能正确的核心 density.For 后者目的、水龙头应该在绕组的
