tributeTRANSFORMER变压器

TRANSFORMER

变压器

Key words

:

transformer; loss; principles and applications

关键词：变压器；损耗；原理与应用

Abstract

摘要

Power plant and substation transformer is one of the Power plant and

substation’

s main equipment. The role is multifaceted transformer not

only

can

increase

the

voltage

to

the

power

consumption

area,

but

also

the

voltage

is

reduced

to

levels

of

use

of

voltage,

in

order

to

meet

electricity needs. In short, the boost and back must be done by the

transformer.

Transmission

power

in

the

power

system

in

the

process

would

have a loss of voltage and power of two parts, the transmission

（传输）

loss

of

the

same

power

and

voltage

when

the

voltage

is

inversely

proportional

（成反比）

to the power loss is inversely proportional to

the square of the voltage. Use of transformers increase the voltage,

reduced

power

transmission

losses.

In

this

article,

we

discuss

the

principles and applications of power transformers.

发电和配电变压器是发 电厂和变电站的主要设备之一。

它是一种多方面的变

压器，

不仅可以提高电压输送到能耗区域，

而且可以降低为各级使用电压以 满足

用电需求。

简而言之，

提高和降低 都必须由变压器完成。

电力系统在输送功率的

过程中将会有电压 和功率两个部分的损耗，

在传输相同的功率，

电压损耗和电压< /p>

成反比，

功率损耗与电压的平方成反比。

利用变压器提高电压降低在传输过程中

的功率损耗。在本文中，我们讨论电力变压器的原 理和应用。

1.

INTRODUCTION

介绍

The high-voltage transmission was need for the case electrical power is

to

be

provided

at

considerable

distance

from

a

generating

station.

At

some

point

this

high

voltage

must

be

reduced,

because

ultimately

is

must

supply

a load. The transformer makes it possible for various parts of a power

system to operate at different voltage levels.

一个远距离的发电厂提供电能需要用高压传输。

在某些程度上这 样的高电压

必须降低，

因为最终必须提供一个负载。

同的电压等级下。

< br>

2. TOW-WINDING TRANSFORMERS

双绕组变压器

A transformer in its simplest form consists of two stationary coils

coupled by a mutual magnetic flux. The coils are said to be mutually

coupled because they link a common flux.

最简形式的变压器包括两个磁通相互耦合的固定线圈。

线圈之所以相互耦合

是因为他们有共同的磁通。

In power applications, laminated steel core transformers (to which

this paper is restricted) are used. Transformers are efficient because

the

rotational

losses

normally

associated

with

rotating

machine

are

absent, so relatively little power is lost when transforming power from

one voltage level to another. Typical efficiencies are in the range 92

to 99%, the higher values applying to the larger power transformers.

在电力的应用中，

层式铁芯变压器被使用。

变压器是高效的，

旋转的机器通

常没有旋转的损失，

因此从一个电压级到另一个电压级的能量传输的能量损失相

对较少。典 型效率的范围是

92%-99%

，上限值适用于大功率变压器。

The

current

flowing

（电流）

in

the

coil

（线圈）

connected

to

the

ac

source is called the primary winding or simply the primary. It sets up

the flux

φ

in the

core, which varies

periodically both in magnitude and

direction. The flux links the second coil, called the secondary winding

or

simply

secondary.

The

flux

is

changing;

therefore,

it

induces

a

voltage

in

the

secondary

by

electromagnetic

induction

in

accordance

with

Lenz’s

law.

Thus

the

primary

receives

its

power

from

the

source

while

the

secondary

supplies

this

power

to

the

load.

This

action

is

known

as

transformer action.

从交流电源流入电流的一侧被称为变压器的一次侧绕组或者是 原边。它在

铁圈中建立了磁通

φ

，它的 幅值和方向都会发生周期性的变化。磁通连接的第二

个绕组被称为变压器的二次侧绕组或 者是副边。

磁通是变化的，

因此根据楞次定

律，

电磁感应

在二次侧产生了电压。

原边从变压器接收电能的同时也在向副边所

带的负荷输送电能。这就是变压器的作用。

3. TRANSFORMER PRINCIPLES

变压器的工作原理

When a sinusoidal voltage Vp is applied to the primary with the

secondary

open- circuited,

there

will

be

no

energy

transfer.

The

impressed

voltage causes a small current I

θ

to flow in the primary winding. This

no-load current has two functions: (1) it produces the magnetic flux in

the core, which varies sinusoidally between zero and

?

φ

m, where

φ

m

is the maximum value of the core flux; (2)and it provides a component

to account for the

hysteresis

and

eddy current losses

in the core. There

combined losses are normally referred to as the core losses.

正弦电压

V

p

作用于原边，并且二 次侧开路，此时是没有能量转移的。外加

电压产生一个小电流

I

θ

流入一次侧绕组中。这个空载电流 有两项功能：

（

1

）在

铁芯中产生电磁通，该磁通在零和

?

φ

m

之间做正弦变化，

φ

m

是铁芯磁通的最大

值；

（

< br>2

）

它的一个分量说明了铁芯中的

涡流

和

磁滞损耗

。

< br>这两种相关的损耗通常

被称为铁芯损耗。

The

no-load

current

I

?

is

usually

few

percent

of

the

rated

full-load

current of the transformer

(about

2 to

5%). Since at no-load the primary

winding

acts

as

a

large

reactance

due

to

the

iron

core,

the

no-load

current

will lag the primary voltage by nearly 90?. It is readily seen that the

current component

I

m

= I

0

sinθ

0

, called the magnetizing current, is 90?

in

phase

behind the primary voltage

V

P

. It is this component that sets up

the flux in the core;

φ

is therefore in phase with Im.

空载电流

I

< br>?

通常是满载电流的

2%

—

5%

。

因为在空载时，

因为铁芯原边绕组

相当于一个很大的电抗，空载电流的相位将滞后于原边电压的相位

90?

左右。显

然可见电流分量

I

m

=

I