Electrical Power : Обучение профессионально-ориентированному чтению

 
 
 
 
Г.К. Кушникова 
 
 
ELECTRICAL POWER 
 
Обучение 
профессионально-ориентированному чтению 
 
Учебное пособие 
 
 
3-е издание, стереотипное 
 
 
 
 
 
 
 
 
 
 
 
 
Москва 
Издательство «Флинта» 
2012 

УДК 811.111(075) 
ББК  81.2Англ-923 
          К96 
 
 
 
 
 
 
 
 
Кушникова Г.К. 
К96    Electrical Power : Обучение профессионально-ориентированному чтению [Электронный ресурс] : учеб. пособие / 
Г.К. Кушникова. – 3-е изд., стер. – М. : Флинта, 2012. –  
104 с.  
     ISBN 978-5-89349-651-2 
 
 Настоящее учебное пособие предназначено для развития навыков чтения оригинальной литературы, получения нужной информации, умения побеседовать по прочитанному тексту и делать сообщения на английском языке. 
 Для студентов электромеханических и электроэнергетических 
специальностей технических вузов. 
УДК 811.111(075) 
ББК  81.2Англ-923 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
ISBN 978-5-89349-651-2                © Издательство «Флинта», 2012 

Contents

Ïðåäèñëîâèå ........................................................................................... 5

Ðàçäåë I

Text One.
Generation of Electricity ......................................... 7
Text Two.
Resistance ................................................................... 8
Text Three.
Electromagnetism .................................................... 10
Text Four.
Electromagnetic 
Induction .................................... 12
Text Five.
Alternating 
Current 
Generator ............................. 14
Text Six.
Three-Phase 
Generator .......................................... 16
Text Seven.
Transmitting 
Alternating 
Current......................... 17
Text Eight.
Alternating Current Motors .................................. 19
Text Nine.
Induction 
Motor...................................................... 20
Text Ten.
Single-Phase 
Motors............................................... 22
Text Eleven.
Induction 
Motors .................................................... 23
Text Twelve.
Direct-Current 
Generators.................................... 24
Text 
Thirteen.
Difference between Alternating- and
Direct-Current 
Generators.................................... 26
Text Fourteen.
Types of Direct-Current Generators ................... 27
Text Fifteen.
Compound 
Generators........................................... 29
Text Sixteen.
Direct-Current 
Motors........................................... 31
Text 
Seventeen. Types of Direct-Current Motors .......................... 32
Text Eighteen.
Uses of DC Machines ............................................ 33
Text 
Nineteen. Compound 
Motors.................................................. 35

Ðàçäåë II

Supplementary Texts

Dry-Type 
Transformers........................................................................ 37
In Coal Mines ........................................................................................ 39
Practical Tests ........................................................................................ 40
Lightning ................................................................................................. 41

Types of Armature Windings .............................................................. 42
AC Generators in Parallel ................................................................... 43

Future Power Sources

Introducion ............................................................................................. 49
Thermoelectric 
Generators.................................................................. 49
The Basic Phenomenon ....................................................................... 50
Materials and Their Parameters......................................................... 50
Devices and Design .............................................................................. 52
Thermionic 
Generators ........................................................................ 54
Principle of Operation ......................................................................... 55

Magnetohydrodynamic Generators

Power from High-Temperature Gas ................................................. 58
The MHD Generator ........................................................................... 58
MHD Generator Cycles...................................................................... 60
Research in MHD ................................................................................. 62
Fuel Cells ... Electrical Energy from Electrochemical Process....... 62
Operating Characteristics and Properties ......................................... 63

Ðàçäåë III

Ñëîâàðü-ìèíèìóì äëÿ ÷òåíèÿ íàó÷íîé ëèòåðàòóðû
íà àíãëèéñêîì ÿçûêå ......................................................................... 65

Ïðåäèñëîâèå

Íàñòîÿùåå ïîñîáèå ïðåäíàçíà÷åíî äëÿ ñòóäåíòîâ ýëåêòðîìåõàíè÷åñêèõ è ýëåêòðîýíåðãåòè÷åñêèõ ñïåöèàëüíîñòåé è ðàññ÷èòàíî íà âòîðîé ýòàï îáó÷åíèÿ àíãëèéñêîìó ÿçûêó â òåõíè÷åñêîì
âóçå.
Îñíîâíîé çàäà÷åé ïîñîáèÿ ÿâëÿåòñÿ íàó÷èòü ñòóäåíòîâ ÷èòàòü
îðèãèíàëüíóþ ëèòåðàòóðó ïî ñïåöèàëüíîñòè ñ öåëüþ ïîëó÷åíèÿ
íóæíîé èíôîðìàöèè, âåñòè áåñåäó ïî ïðî÷èòàííîìó òåêñòó è
äåëàòü ñîîáùåíèÿ íà àíãëèéñêîì ÿçûêå. Ïîñîáèå òàêæå ïîìîãàåò ñòóäåíòàì îâëàäåòü ðÿäîì òåõíè÷åñêèõ òåðìèíîâ ýëåêòðîìåõàíè÷åñêèõ 
è 
ýëåêòðîýíåðãåòè÷åñêèõ 
ñïåöèàëüíîñòåé.
Ïîñîáèå ñîñòîèò èç òðåõ ðàçäåëîâ. Ïåðâûé ðàçäåë ñîäåðæèò
19 òåêñòîâ è óïðàæíåíèé ê íèì. Êàæäûé òåêñò îõâàòûâàåò ïðèáëèçèòåëüíî 1500–2000 ïå÷àòíûõ çíàêîâ. Òåêñòû ïîäîáðàíû èç
îðèãèíàëüíîé 
òåõíè÷åñêîé 
ëèòåðàòóðû. 
Äëÿ 
áîëüøåé 
íàãëÿäíîñòè òåêñòû ñíàáæåíû ðèñóíêàìè è ÷åðòåæàìè.
Âî âòîðîì ðàçäåëå äàíû òåêñòû äëÿ âíåàóäèòîðíîãî ÷òåíèÿ.
 
òðåòüåì 
ðàçäåëå 
äàí 
ñëîâàðü-ìèíèìóì. 
Ñëîâàðü 
èìååò
öåëü îáëåã÷èòü è óíèôèöèðîâàòü ïðîöåññ îáó÷åíèÿ ÷òåíèþ, ïåðåâîäó è ðåôåðèðîâàíèþ íàó÷íûõ òåêñòîâ ïî ñïåöèàëüíîñòè. Îí
ìîæåò áûòü èñïîëüçîâàí è êàê ñïðàâî÷íèê ïðè ñàìîñòîÿòåëüíîé
ðàáîòå.
ßçûê, ñ ïîìîùüþ êîòîðîãî èçëàãàþòñÿ íàó÷íûå è òåõíè÷åñêèå ôàêòû, ñòàâèò ïåðåä ñòóäåíòàìè ðÿä ïðîáëåì, è îäíîé èç
ñàìûõ 
âàæíûõ 
ÿâëÿåòñÿ 
«âîêàáóëÿð». 
Íàó÷íûå 
è 
òåõíè÷åñêèå
òåêñòû 
ñîäåðæàò 
áîëüøîå 
êîëè÷åñòâî 
òåðìèíîâ. 
Ýòà 
ïðîáëåìà
ðåøàåòñÿ ñ ïîìîùüþ ñóùåñòâóþùèõ ðàçëè÷íîãî ðîäà îòðàñëåâûõ
ñëîâàðåé, êðîìå òîãî, áîëüøîå êîëè÷åñòâî ñëîâ ÿâëÿþòñÿ ìåæäóíàðîäíûìè.
Íàèáîëüøóþ æå òðóäíîñòü ïðåäñòàâëÿþò ïîëóíàó÷íûå, ïîëóòåõíè÷åñêèå ñëîâà (íåêîòîðûå ìåòîäèñòû íàçûâàþò èõ îáùåíàó÷íûìè ñëîâàìè), êîòîðûå õàðàêòåðíû äëÿ âñåõ îòðàñëåé íàóêè, èìåþò ðÿä çíà÷åíèé è ÷àñòî èñïîëüçóþòñÿ èäèîìàòè÷åñêè.
Ñóùåñòâóåò 
òàêæå 
ðÿä 
ãëàãîëîâ, 
ïðèëàãàòåëüíûõ, 
íàðå÷èé, 
êî

òîðûå, ïî ñóùåñòâó, íå ÿâëÿþòñÿ íàó÷íûìè, íî ïðèíàäëåæàò ê
íàó÷íîé 
ôðàçåîëîãèè. 
Ìàêñèìàëüíîå 
êîëè÷åñòâî 
òàêèõ 
ñëîâ 
è
âîøëî â äàííûé ëåêñè÷åñêèé ìèíèìóì.
Âñå ñëîâà ðàñïîëîæåíû â àëôàâèòíîì ïîðÿäêå. Êàæäîå îòäåëüíîå ñëîâî, áóäü òî îñíîâíîå èëè ïðîèçâîäíîå, äà¸òñÿ êàê
ñàìîñòîÿòåëüíàÿ 
ëåêñè÷åñêàÿ 
åäèíèöà. 
Ñëîâà, 
îäèíàêîâûå 
ïî
íàïèñàíèþ è ïðîèçíîøåíèþ, íàïðèìåð ñóùåñòâèòåëüíîå è ãëàãîë, 
äàþòñÿ 
îäèí 
ðàç. 
Ñëîâî, 
îäèíàêîâîå 
ïî 
íàïèñàíèþ, 
íî
èìåþùåå 
äðóãîå 
ïðîèçíîøåíèå, 
âûäåëÿåòñÿ 
â 
îòäåëüíóþ 
ñëîâàðíóþ 
ñòàòüþ. 
Ïðåäëîã, 
õàðàêòåðíûé 
äëÿ 
äàííîãî 
ãëàãîëà,
ñòàâèòñÿ â ñêîáêàõ ïîñëå ïåðåâîäà ýòîãî ãëàãîëà. Íåïðàâèëüíî
îáðàçóþùèåñÿ ôîðìû ãëàãîëîâ ïðèâîäÿòñÿ â ñêîáêàõ. Åñëè â
ñêîáêàõ äàíà îäíà ôîðìà ãëàãîëà, çíà÷èò Past è Participle II ñîâïàäàþò. 
 
ñëîâàðíûõ 
ñòàòüÿõ 
ïðèâîäÿòñÿ 
íåêîòîðûå 
ôðàçåîëîãè÷åñêèå 
ñî÷åòàíèÿ, 
êîòîðûå 
÷àñòî 
âñòðå÷àþòñÿ 
â 
àíãëèéñêîé
íàó÷íîé 
ëèòåðàòóðå.

Ðàçäåë I

TEXT ONE

GENERATION OF ELECTRICITY

Our study of electricity will bå limited to methods of generation,
distribution and application in furnishing motive power for machinery. As this is not a highly technical study, the electron theory of
the nature of electricity will not be discussed.
Historically, knowledge of electrical manifestation goes back to
the early Greeks who noticed that amber, after being rubbed, had
the power to attract feathers or small bits of straw. Through the ages
many people have experimented with and studied the nature of this
strange power, and by their efforts it has been brought under control
and made one of man’s most useful servants.
Before studying the way in which electrical power is generated,
certain terms must be explained and certain manifestations must be
discussed in order to make the study meaningful. The explanations
given here are made as simple and nontechnical as possible.
Electromotive force (emf) is the force or pressure that causes
electric current to flow. The unit of measure of this force is the volt.
Electromotive 
force 
is 
sometimes 
called 
“potential” 
or 
“voltage”.
Electric current will flow in a wire when sufficient voltage is present.
The unit of measurement of electric current flow is the ampere. Volts
and amperes are measured by dial instruments called voltmeters and
ammeters.
The amount of electric power that is delivered bó à generator or
is consumed by a motor or other power device is the product of the
pressure and the flow. Thus, power = volts x amperes. The unit of
measure of power is the watt. Therefore, watts = volts x amperes.
Instruments for indicating or recording watts are called wattmeters.
For designating large amounts of power the term “kilowatt” or kw,
which means one thousand watts, is used.

EXERCISES

I. Read and translate the text.
Remember the words which are new for you.
II. Give Russian equivalents.
Electromotive force; the measure of electric power; wattmeter;
dial instrument; voltmeter; ammeter.
III. Give Russian equivalents, paying attention to the suffixes in
English words:
to 
explain-explanation; 
to 
consume-consumer-consumption; 
to
indicate-indicator-indication; 
to 
generate-generator-generation.
IV. Answer the following questions:
1. What is electromotive force?
2. What electrical units do you know?
3. What is the volt?
4. What is the ampere?
5. What is the watt?
6. What instruments are used for measuring emf and the electric
current flow?
7. What is the kilowatt and when is it used?
V. Speak on:
1) electromotive force;
2) the measure of electric power.

TEXÒ TWO

RESISTANCE

Resistance is the property of any material to oppose the flow of
electricity through it. The unit of measure of this resistance is the
ohm. The resistance of a conductor varies directly to its length and
inversely to its cross-sectional area. Thus a long thin wire would
have a high resistance in ohms and a short thick wire would have a
low resistance.
The voltage required to make a current flow in a conductor depends upon the resistance. A pressure of 1 volt will make a current of
1 ampere flow through a resistance of 1 ohm. This relationship is
expressed in the formula

I = U/R,

where I is the current in amðåres, U — pressure in volts and R – resistance in ohms. This formula may be transposed

U = IR or R = U/I,

so that when any two of the values in the formula are known the
other may be found. This formula is known as Ohm’s Law.
Electric conductors usually consist of wires or cables made of
copper. Copper is used because it is the best conductor and relatively cheap. Every substance is a conductor to some degree, but
the metals are the best.
Electric insulators are materials that allow almost no electricity
to pass through them. These materials are also called nonconductors. 
Typical 
commercial 
insulators 
are 
rubber, 
silk, 
cotton,
mica, porcelain, glass, dry paper and etc. Dry air and oils are
good insulators too. Wire conductors are usually covered with insulation.
Electric circuits. – In order to use electric currents for transmitting power they must be sent through insulated conductors arranged to form complete paths. That is, the conductor must start at
the generator, go to the motor, through it and return to the generator. If there is a break in the path, current will not flow. These
paths are called electric circuits. Circuits may be series, shunt or
compound. (For example, see diagrams shown in Figure 1.)

Fig. 1. Circuits

COMPOUND 
OR 
SERIES 
PARALLEL

SHUNT

LAMPS

SERIES

EXERCISES

I. Read and translate the text.
II. Give Russian equivalents:
cross-sectional area, to be directly proportional to, to be inversely 
proportional 
to, 
relationship, 
in 
order 
to, 
the 
arrangement of conductors, series circuit, shunt circuit, compound circuit.
III. Answer the following questions:
1. What is the resistance?
2. In what units is the electrical resistance measured?
3. How does the resistance of a conductor vary?
4. We have two wires. One of them is long and thin.
The other is short and thick. Which of them will have higher resistance?
5. What is Ohm’s Law?
6. What is a conductor?
7. What is an insulator?
8. What substance is widely used as a conductor?
9. What substances are used as insulators?
    10. What is an electric circuit?
    11. What kinds of electric circuits do you know?
IV. Speak on:
1. resistance; 2. electric conductors; 3. electric insulators;
4. electric circuits.
V. Look at Fig. 1 and describe three kinds of electric circuits.

TEXT THREE

ELECTROMAGNETISM

We are all familiar with permanent magnets. Permanent magnets, however, are not suitable for use in large electric generators,
and so the electromagnets must be used.
Magnetism can be produced by electric currents. In fact every
current-carrying conductor has a magnetic field about it. When a
current-carrying wire is formed into a coil the magnetic field, which
is the space occupied by magnetic lines of force, passes through the
coil and around the outside, as shown in Fig. 2.

If a bar of iron or steel is placed within the coil, the field is concentrated in it and it becomes a magnet, or, more properly, an electromagnet. If the iron or steel core and the coiled wire are arranged as
shown in Fig. 3, the magnetism follows the core and is concentrated at
the gap G. This concentrated form of the magnet field is very useful in
generators, as will be shown. The strength of any magnetic field thus
produced depends on the amount of current flowing in the wire, and
the number of turns of wire. Many turns of wire and a strong current
will produce a strong electromagnet and thus a strong field.

EXERCISES

I. Read and translate the text.
II. Read the words and give Russian equivalents:
magnet, 
magnetic, 
magnetism, 
electromagnetism, 
electromagnet, 
magnetic 
field, 
magnetic 
lines 
of 
force, 
current-carrying
conductor, the number of turns of wire.
III. Speak on electromagnetism using Figs. 2 and 3.

Fig. 3.  Electromagnet with concentrated field

N            S

G

Fig. 2. Electromagnet
S

N

TEXT FOUR

ELEÑTROMAGNETIC 
INDUCTION

If a conductor (wire) is moved across this magnetic field so
that, in effect, it cuts across “the lines of magnetic force” a voltage
will be produced in it. This action is illustrated in Fig. 4.

The effect would be the same if the conductor were stationary
and the field were moved. This phenomenon illustrates the principle
of electromagnetic induction which is stated as follows:
“When a conductor cuts or is cut by a field of magnetic force
an electromotive force is produced in that conductor”. The direction
in which the current will flow in the conductor is determined by the
direction of motion of the conductor. As shown in Fig. 4, the field
direction is from N to S (north to south pole of the magnet); the direction of the motion of the conductor is down and the current direction is as shown by the arrows. If the movement of the conductor
were upward the direction of the current would be the opposite of
that shown in the illustration.
The 
voltage 
produced 
in 
the 
conductor 
depends 
on 
the
strength of the field and the speed of the conductor. The stronger
the field and the faster it is cut by the conductor the greater will
be the voltage.

Fig. 4. Principle of electromagnetic induction

VOLTMETER

A

N                         S

A