1. Ответьте на вопросы

1. What is the purpose of using relays?

2. What is the consequences of contacts in turns close and complete the circuit breaker trip coil circuit?

3. What would happen if the value of actuating quantity is increased?

4. What is reset level?

5. How many types of relays are there associated with time? Which?

6. What is the definition of operating time of relay?

7. What is Reset time of Relay?

8. What parameters relays protection types are mainly based?

9. How do Based on operation mechanism protection relay can be divided?

10. What kind of relay categorizations do you know that based on characteristic?

2. Найдите синонимы

Automatic, close, worth, complete, robust, increase, exceed, finish, normal, healthy, growth, perfunctory, value, shut, transcend, ordinary.

Найдите антонимы

Automatic, complete, healthy, increase, close, normal, static, manual, nonstandard, dynamic, unhealthy, incomplete, decrease, open.

3. Переведите следующие слова и выражения на английский язык

1. Oпределение защитного реле.

2. Электрические цепи.

3. Автоматический предохранитель.

4. Электромагнитное воздействие.

5. Система питания.

6. Операционный механизм.

7. Электромагнитное реле.

8. Статическое реле.

4. Переведите следующие слова и выражения на русский язык

1. Mechanical relay.

2. Instantaneous relays.

3. Closed contacts.

4. Specific contacts.

5. Electromagnetic relay.

6. Semiconductor switches.

7. Voltage restraint over current relay.

8. Programmed switches.

9. Stepped characteristic.

Generators

The dynamo invented by Faraday in 1831 is certainly a primitive apparatus compared with the powerful, highly efficient generators and alternators that are in use today» Nevertheless, these machines operate on the same principle as the one invented by the great English scientist. When asked what use his new invention had, Faraday asked in his turn: "What is the use of anew-born child?" As a matter of fact, "the new-born child" soon became an irreplaceable device we cannot do without.

Although used to operate certain devices requiring small currents for their operation, batteries and cells are unlikely to supply light, heat and power on a large scale. Indeed, we need electricity to light up millions of lamps, to run trains, to lift things, and to drive the machines. Batteries could not supply electricity enough to do all this work.

That dynamo-electric machines are used for this purpose is a well-known fact. These are the machines by means of which mechanical energy is turned directly into electrical energy with a loss of only a few per cent. It is calculated that they produce more than 99.99 per cent of all the world's electricpower.

There are two types of dynamos, namely, the generator and the alternator. Theformer supplies direct current which is similar to the current from a battery and the latter, as its name implies provides alternative current.

To generate electricity both of them must be continuously provided with energyfrom some outside source of mechanical energy such as steam engines, steamturbines or water turbines, for example.

Both generators and alternators consist of the following principal parts: an armature and an electromagnet. The electromagnet of a direct current generator is usually called a stator for it is in a static condition while the armature (the rotor) is rotating.

Alternators may be divided into two types: 1. alternators that have a stationary armature and a rotating electromagnet; 2. alternators whose armature serves as a rotor but this is seldom done. In order to get a strong e.m.f., the rotors in large machines rotate at a speed of thousands of revolutions per minute (r.p.m.). The faster they rotate, the greater the output voltage the machine will produce.

In order to produce electricity under the most economical conditions, thegenerators must be as large as possible. In addition to it, they should be kept as fully loaded as possible all the time. It is interesting to note here that the biggest generators ever installed at any hydroelectric station in the world are those installed in the USSR. As you are likely to remember the Bratskaya hydroelectric station is equipped with 225,000 kilowatt (kW) generators. Soviet scientists constructed more powerful generators which are installed at the Krasnoyarskaya station. The Konakovskaya, the Zaporozhskaya and the Uglegorskaya steam power-stations have large rated capacity.

Our industry produces even greater power installations of 1,200 MW for the steampower plants which play such an important par, in the electrification plan of theUSSR.