Vocabulary

Load points – значения нагрузки

Scattered over the surface area – рассредоточены по поверхности

To meet requirements – отвечать требованиям

Waveform of the voltages – волновая характеристика напряжения

Selection of generators – выборочное подключение генераторов

Conditions must be met – условия должны быть выполнены

Exactly equal – абсолютно равны

Phase rotation – чередование фаз

Exact phase opposition – точное противоположение фаз

At the instant of paralleling – в момент введения в параллель

a bright-lamp synchronizing method - метод синхронизации на вращение света

dark-lamp synchronizing method – метод синхронизации на погасание света

throttle – дроссель

tap-changing devices - приборы переключения ответвлений

5. Answer the questions.

1. What is it necessary to do to assure continuity of the power supply within prescribed limits of frequency and voltage at all the load points scattered over the surface area?

2. Enumerate 4 main requirements for parallel operation.

3. What is the synchronizing? Describe the synchronizing procedure.

4. What conditions must be met at the time of synchronizing?

5. Why are all these conditions necessary?

6. What do we call running and incoming machines?

7. What synchronizing methods do you know?

8. What are the system frequency and the division of active power among the generators controlled by?

6. Complete the sentences while translating word combinations into English.

1. Several alternators in parallel (соединяются) by various (линиями передачи), in a well-coordinated and optimized manner such that the operation would be most economical.

2. (Волновая характеристика напряжения) should be the same, and therefore the gen­erators should be of the same type, though their (величина киловольт-ампер) may (отличаться).

3. The alternators running should have (первичные движители) whose (характеристики скорости и нагрузки) are the same.

4. One alterna­tor is placed in parallel with one or more other alternators only when (дополнительная нагрузка) (требует) it.

5. Those alternators already (несущие ток) are known as the running machines, while that which (должна быть включена в систему) is known as the incom­ing machine.

6. (Напряжение каждой фазы) which are to be connected to each other must be in (точное противоположение фаз).

7. A synchroscope or (метод синхронизации на вращение света) or (метод синхронизации на погасание света) is used for indicating the appropriate moment for syn­chronization.

8. The system frequency and (распределение активной мощности) among the generators are controlled by means of prime-mover throttles regulated by governors and (автоматическими регуляторами частоты).

7. Check your comprehension of the text by finding the right variant of questions:

1. Which of the following is not a necessary requirement for parallel operation?

a) generators must have the same voltage rating;

b) generators must have the same frequency rating;

c) generators must have the same speed;

d) the waveform of the voltages should be the same.

2. What requirements should be met at the time of synchronizing?

a) the effective voltage of the incoming generator must be exactly equal to that of the others;

b) the phase rotation or sequence of the running and incoming generators must be the same;

c) the individual phase voltages which are to be connected to each other must be in exact phase opposition;

d) all these above.

3. What method is used for indicating the appropriate moment for synchronization?

a) synchronoscope;

b) a bright-lamp synchronizing method;

c) a dark-lamp synchronizing method;

d) all the three