Task 5. Think of the best translation to the following words and word combinations.

a) widely distributed;

b) convert energy in its final physical form;

c) the design of a range of related devices;

d) computer design;

e) reduce power losses;

f) the real-time control;

g) application of circuits;

h) major developments;

i) the replacement of analogue systems with digital systems;

j) power transmission;

k) be proficient in implementation of technical ideas.

 

Task 6. True or false?

1) Energy is rarely distributed in nature.

2) Electrical engineering is the widest field of engineering and it is divided into four branches.

3) Electronic engineering deals with the design of memory systems and central processing units.

4) The ability of a country to make energy available at an acceptable cost is an indicator of technical development.

5) In general electrical engineering deals with three main problems: the generation, transmission and distribution of energy.

 

Task 7. Fill in the gaps using words and word combinations from the text.

1) Computer engineers manufacture memory systems, central processing units and….

2) Energy is the basis of any technical and … .

3) One of the major developments in the field of communications and control is the replacement of analogue systems with… .

4) The energy consumption per capita in a country exhibits differences between highly industrialized and … .

5) This creates problems of transporting the energy from…to the point of demand and of converting it in … .

6) Several important developments appeared in the field of electric power and machinery. One of these is the ability to transmit power at extremely high voltages in both…, reducing power losses.

 

Task 8. Answer the questions.

1) What alternative types of energy do you know?

2) What is an indicator of the state and technical development of any country?

3) What problems does electrical engineering deal with?

4) What devices does electrical engineering design?

5) What are four main branches of electrical engineering?

6) Can you give a few examples of important developments that appeared in electric power and machinery?

7) What does computer engineering manufacture?

8) What does electrical engineering necessitate the practicing student to do?

 

Task 9. Give the summary of the text.

Step 2. ELECTRICAL DRIVE

 

Task 1. Pronounce correctly the following words and word combinations. Learn them by heart.

 

Electrical drive – электропривод

power rating – максимально допустимая мощность

conversion – превращение, преобразование

to estimate – оценивать

constant- speed drive – двигатель с постоянной частотой вращения

predominance – превосходство, преобладание

steam turbine – паровая турбина

hydraulic drive system – гидропривод

pneumatic drive system – пневмопривод

pump – насос

hydrostorage plant – гидроузел

torque – вращающий момент

forced air ventilation – принудительная вентиляция

to enclose – окружать, обрамлять, ограждать

to submerge – погружать под воду, затоплять

to expose – выставлять, подвергать себя

hazardous fuel – опасные виды топлива

to emit – излучать, выпускать, извергать

exhaust fumes – отработавшие газы, выхлопные газы

at a moment’s notice – немедленно, сразу

service requirements – техническое обслуживание

modest – скромный, умеренный

high dynamic performance – высокие динамические характеристики

considerable short- time overload capacity – чрезвычайно высокая способность выдерживать перегрузки в течение короткого промежутка времени

elevated temperature – повышенная температура

fatigue – усталость (металлов)

compatible with – совместимый с

foot- mounted – смонтированный на полу

flange- mounted – прифланцованный двигатель

outer rotor – внешний ротор

to supplement – пополнять, добавлять

propulsion – толчок, тяга

on- board – встроенный

storage battery – аккумуляторная батарейка

fuel and solar cells – топливные и солнечные элементы

power-to-weight ratio – удельная мощность

 

Task 2. Read and translate the text.

ELECTRICAL DRIVE

  The mechanical form of energy is particularly important. It is needed in widely varying power ratings wherever physical activities take place, involving the transportation of goods and people or industrial production processes. For this final conversion at the point of utilization, electromechanical devices in the form of electrical drives are well-suited. It is estimated that about half the electricity generated in an industrial country is eventually converted to mechanical energy.

Most electrical motors are used in constant-speed drives that do not need to be controlled except for starting, stopping or protection.

  The predominance of electrical drives (as compared with steam turbines, hydraulic drive system, diesel engines, pneumatic drive system) is caused by several aspects:

1. Electrical drives are available for any power (from the power in electronic watches to the power for driving pumps in hydro storage plants).

2. They cover a wide range of torque and speed.

3. Electrical drives are adaptable to almost any operating conditions such as forced air ventilation or totally enclosed, submerged in liquids, exposed to explosive or radioactive environments. They do not require hazardous fuels and do not emit exhaust fumes. The noise level is low compared, for instance, with combustion engines.

4. Electrical drives are operable at a moment’s notice and can be fully loaded immediately. There is no need to refuel, nor warm-up the motor. The service requirements are very modest, as compared with other drives.

5. Electrical drives are easily controllable. The steady state characteristics can be reshaped almost at will. High dynamic performance is achieved by electronic control.

6. Electrical drives have a considerable short-time overload capacity.

7. Since there are no elevated temperatures causing fatigue, long operating life can be expected.

8. Electrical motors are built in a variety of designs to make them compatible with the load; they may be foot-or flange-mounted, or the motor may have an outer rotor etc.

       Machine tools can now be driven by a multitude of individually controlled motors producing the mechanical power exactly where, when and in what form it is needed. As would be expected, this long list of remarkable characteristics is to be supplemented by disadvantages of electrical drives which limit their use.

1. The dependence on a continuous power supply causes problems with vehicle propulsion. An electric energy source must be carried on-board, which is usually bulky, heavy and expensive (storage battery, rotating generator with internal combustion engine, fuel or solar cells).

2. Electrical motors are likely to have a lower power-to-weight ratio than, for instance, high pressure hydraulic drives.