Файл: Методическое пособие для студентов iv курса очного и заочного обучения специальности 26. 05. 07 "Эксплуатация судового электрооборудования и средств автоматики".doc

4. Match the synonyms.

a) to drive, number, to use, to install

b) quantity, to employ, to mount, to operate
5. Answer the questions.

1. Why are induction motors widely used in all industries?

2. What are induction motors afforded to do on board ships?

3. What do we call "induction motors"?

4. What are the constructive elements of a cage motor?

5. What is the operation of a three-phase cage motor principally based on?

6. How is the rotating magnetic field established?

7. How many revolutions does the magnetic field do during one cycle of the current reversal if the stator winding has one pair of poles?

8. What do we call the speed of rotation?

9. What do we call the value by which the rotor speed of rotation smaller than the stator speed of rotation?

10. In what way can we define the rotor speed of rotation?

11. What is the slip?

12. What exactly are the mechanisms on board ships which are driven by a three-phase cage motor?

6. Speak about induction motors.

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UNIT VIII. ELECTRIC SPECIAL PURPOSE MACHINES

1. Read and remember the following words and word combinations.

electrical special purpose machine	электрическая машина специального назначения
rotary converter	вращающийся преобразователь
static converter	статический преобразователь
commutator-brushgear transition	коллекторно-щеточный переход
magnetic amplifier	магнитный усилитель
rotary amplifier	электромашинный усилитель
instant readiness	мгновенная готовность
resistance to moister and vibration	влаго- и вибростойкость
automatic control and regulating circuits	схемы автоматического управления и регулирования
adjustable-potential system	система генератор - двигатель
cross field	поперечное поле
magnification ratio	коэффициент усиления
inertia capability	инерционность
overload capacity	перегрузочная способность
linearity	линейность
symmetry	симметричность
rotational speed feedback	обратная связь по частоте вращения
synchronous transmission system	система синхронной связи
slip-ringed selsyn	контактный сельсин

2. Read and translate the text.

ELECTRIC SPECIAL PURPOSE MACHINES

On board ships separate electrical energy consumers (radiocommunication, electric radionavigational instruments etc.) require special sources of energy, the main electrical properties of which (voltage, the kind of current, frequency) are different from those of shipboard electric power station. For the purposes of converting electrical parameters of shipboard electric power station into required ones such machines as converters are used. Rotary converters may be either multiarmatured or one-armatured. The general disadvantage of all rotary converters is both the moving contact in the commutator-brushgear transition and the rotating parts, which makes the converters considerably less reliable and harder to operate. At present time static converters are widespread on board ships. They are deprived of the drawbacks indicated above.

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Another variety of an electric special purpose machine is amplifiers. They are distinguished as magnetic amplifiers and rotary amplifiers. Magnetic amplifiers (MA) have acquired a wide application on board ships being designed for automatic regulation, monitoring and control of various marine sets. They are advantageous in not having moving parts, being simple in construction and easy in operation, possessing high reliability and efficiency, being characterised by instant readiness and resistance to moisture and vibration. Magnetic amplifiers are provided to control a big power by expending a small one.

Rotary amplifiers (RA) find application in automatic control and regulating circuits of marine generators and servomotors included into the adjustable-potential systems. Depending on its capacity a rotary amplifier may operate as either an exciter or a generator of the system. The most widespread type of a rotary amplifier is an amplidyne owing a cross field. It is a d.c. generator specially constructed with a number of advantageous features: a big magnification ratio, small inertia capability, a big overload capacity etc.

Another electric special purpose machine is a tachogenerator. It is designed for converting the speed of rotation of the shaft possessed by machines and mechanisms into the proportional electric voltage. A tachogenerator is required to keep linearity and symmetry of an output characteristic within the entire range of the change of either the speed of rotation or the direction of rotation. On board ships d.c. and a.c. tachogenerators are used to measure the speed of rotation of propulsion shafts and other mechanisms. They are also provided in automatic systems to obtain the rotational speed feedback.

Synchronous transmission systems are called selsyn systems. Various instruments designed for controlling the operation of the ship base themselves on selsyns. Such instruments as engine and bridge telegraphs, a gyro-pilot, a gyro-compass, tachometres of propulsion shafts, logs etc. are installed to ensure the control of steering gear positions, the operation of the boilers, the ship's speed and the direction of the ship's motion.

A selsyn is composed of both the stator and the rotor. In construction, selsyns are divided into those provided with slip-rings and those deprived of them. Slip-ringed selsyns, in their turn, may be equipped with either the primary one-phase field winding mounted on the stator and having salient poles or the secondary three-phase synchronisation winding mounted on the rotor and having non-salient poles.
3. Match the following English and Russian word combinations.

a) on board ship, for the purpose of, overload capacity, instant readiness, to acquire a wide application, deprived of drawbacks

b) мгновенная готовность, перегрузочная способность , лишенный недостатков, получить широкое применение, в целях, на борту судна
4. Answer the questions.

1. For what purposes are converters used?

2. What types of converters do you know?

3. Which type of converter is advantageous on board ships? Why?

4. What types of amplifier do you know?

5. Why has a magnetic amplifier acquired a wide application on board ships?

6. What is a magnetic amplifier designed for?

7. Where does a rotary amplifier find application?

8. What may a rotary amplifier operate as depending on its capacity?

9. Which type of rotary amplifier is the most widespread on board ships? Why?

10. What is a tachogenerator designed for?

11. What are D.C. tachogenerators and a.c. tachogenerators used for on board ships?

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12. What types of synchronous transmission system do you know?

13. What instruments base themselves on a selsyn? What are they responsible for?

14. What parts is a selsyn composed of?

15. What types of selsyn do you know?
5. Complete the following sentences with the correct -ing and - ed forms. Select the right verb from the box using it once only:

own	possess	have	assemble	mount
obtain	short-circuit	equip	construct	characterize
range	drive

1.The stator is found in the frame with the core . . . inside and … of 0,35-0,5mm electrical steel laminations.

2. A lot of shipboard alternators operate at the speed of rotation . . from 500 to 1500rev/min.

3. Magnetic amplifiers are electric special-purpose machines . . by instant readiness and resistance to moisture and vibration.

4. An amplidyne is a D.C. generator specially . . . with a number advantageous features.

5.The most widespread type of rotary amplifier is an amplidyne . . a cross field.

6. Slip-ringed selsyns may have either the primary one-phase field winding . . . salient poles or the secondary three-phase synchronization winding . . . non-salient poles.

7. Three-phase cage motors are induction motors . . . ship's auxiliaries, anchor-mooring mechanisms, cranes, winches.

8. The core and aluminium legs . . . from their ends can be found in the core slots.

9. The cores of the poles have the field windings . . . their supply through slip-rings and brushes.

10. A great deal of ship alternators have the rotor . . . with salient poles.
6. Fill the gaps after the modal verbs with the Passive Infinitive.

1. The copper and aluminium legs can . . . (find) in the core slots.

2. The way in which the rotating field is established in the stator m . . . (describe) as follows.

3. The current value can . . . (adjust) by varying the air-gap of reactor magnetic conductor.

4. Measuring instruments should . . . (rate) in accordance with the voltage indicated above.

5. Slip-ringed selsyns can . . . (provide) with the primary on phase field winding.

6. Insulation stands must . . . (use) to protect personnel against a phase voltage.

7. Insulation gloves should . . . (put) on when it is necessary to withstand a working voltage of an electrical set.

8. If the rules of the electrical maintenance and safety are not observed, the normal state of the equipment may . . . (break).

9. The troubles must . . . (eliminate) in time.

10. The test procedure of this autotransformer should . . . (do) in accordance with the safety rules.
7. Speak about electrical special purpose machines.

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UNIT IX. SHIP’S POWER PLANTS AND NETWORKS

1. Read and remember the following words and word combinations.

power plant (station)	электростанция
lighting	осветительная
combined	комбинированная
emergency	аварийная
for electric propulsion	электродвижения
auxiliary	вспомогательная
distribution gear (switchgear)	распределительное устройство
primary motor	первичный двигатель
mode of control	способ управления
rated voltage	номинальное напряжение
partially automated	частично автоматизированный
accommodate	размещать
mode of installation	способ установки
fastening	крепление
consumer	потребитель
generator units	генераторные агрегаты
exert	осуществлять, выполнять
essential	основной, (зд.) ответственный
coastal power supply board	щит питания с берега
mode of operation	режим работы
converter	преобразователь
waterproof	водонепроницаемый
hermetic	герметичный
switchgears equipment	аппаратура распределительных устройств
switching	коммутационная
protective	защитная
switching-protective	коммутационно-защитная
measuring	измерительная
control	регулировочная
signaling	сигнальная
knife switch	рубильник
knife-blade-type switch	переключатель рубящего типа
packet switch	пакетный выключатель/переключатель
control over	контроль за
control of	регулирование /чего-либо/
excitation controllers	регуляторы возбуждения
light/audible alarm	световая/звуковая сигнализация
network	сеть
power mains	силовая сеть
general lighting network	сеть основного освещения
ship's accommodations	освещение судовых помещений
outside	наружного освещения
hold	трюмного освещения
battery-powered emergency	аккумуляторного аварийного
portable low-voltage	низковольтного переносного -
light current installation	установка слабого тока
engine telegraph	машинный телеграф
rudder telegraph	рулевой телеграф
accessories	арматура
vanish	исчезать
bucking transformer	понижающий трансформатор
plug-transformer	штепсель-трансформатор
salinometer	соленомер
pyrometer	пирометр
log	лаг
radio pelorus	радиопеленгатор
mutual protective shell	общая защитная оболочка
guard	предохранять, защищать
moisture	влага
radial direction	радиальное направление
longitudinal direction	продольное направление
iron-clad	панцирный
shielded	экранированный
interference	помеха
radio reception	радиоприем

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