AC power transmission

AC power transmission is the transmission of electric power by alternating current. Usually transmission lines use three phase AC current. In electric railways, sometimes single phase AC current is used as traction current for railway traction.

Today, transmission-level voltages are usually considered to be 110 kV and above. Lower voltages such as 66 kV and 33 kV are usually considered sub-transmission voltages but are occasionally used on long lines with light loads. Voltages less than 33 kV are usually used for distribution. Voltages above 230 kV are considered extra high voltage and require different designs compared to equipment used at lower voltages.

Bulk power transmission

A transmission grid is a network of power stations, transmission circuits, and substations. Energy is usually transmitted within the grid with 3-phase alternating current (AC).

The capital cost of electric power stations is so high, and electric

demand is so variable, that it is often cheaper to import some portion of the variable load than to generate it locally. Because nearby loads are often correlated (hot weather in the Southwest portion of the United States might cause many people there to turn on their air conditioners), imported electricity must often come from far away. Because of the irresistible economics of load balancing, transmission grids now span across countries and even large portions of continents. The web of interconnections between power producers and consumers ensures that power can flow even if one link is disabled.

XII. Составьте письменный реферат текста.

UNIT 6.

I. Определите значение данных слов и словосочетаний,

Используя англо-русский словарь.

power-line, fuel-burning, coal-fired, corona discharge, phase-shifting, capacitance, capacitor bank, resistive, inductance, impedance, fiber optic cable, ground conductor, common carrier

pilot-wire, utilities, stand-alone, reactive

II. Проверьте по словарю произношение данных интернациональных слов.

Corona, asynchronous, reactive, compensator, phase, factor, telecommunication, commercial, cable, structure.

III. Проанализируйте и переведите на русский язык следующие прилагательные, образованные с помощью следующих суффиксов.

-ant: significant, vacant, reluctant, redundant;

-ent: prominent, dependent, violent, frequent;

-able: controllable, reliable, available, variable;

-ous: asynchronous, onerous, ambitious, generous.

IV. Переведите следующие беспредложные терминологические словосочетания, состоящие из существительного, причастия I (герундия) и существительного, на русский язык.

Phase-shifting transformers

fault-sensing protection relays

fuel-burning power plants

voltage regulating system

load balancing economics

V. Переведите следующие терминологические словосочетания, состоящие из существительного, причастия II и существительного, на русский язык.

water-filled pipe

coal-fired power plants

pressure-operated switch

keyboard-controlled machine

VI. Переведите следующие беспредложные терминологические словосочетания, состоящие из существительных, на русский язык.

construction cost