Power system
Electricity is generated at central power stations and then transferred to loads (i.e, Domestic, Commercial and Industrial) through the transmission and distribution system. A combination of all these systems is collectively known as an Electric Power System.
A power System is a combination of central generating stations, electric power transmission system, Distribution and utilization system. Each one of these systems is explained in detail in the next sections.
Fig. 1: Basic Structure of an Electric Power System (Energy Supply System)
Electric Energy Supply System
The transmission of electric power from a power station to consumers’ premises is known as the electric supply system.
An electric supply system consists of three principal components viz., the power station, the transmission lines and the distribution system. Electric power is produced at the power stations which are located at favourable places, generally quite away from the consumers. It is then transmitted over large distances to load centres with the help of conductors known as transmission lines. Finally, it is distributed to a large number of small and big consumers through a distribution network, supply system can be broadly classified into (i) d.c. or a.c. system (ii) overhead or underground system.
Nowadays, 3-phase, 3-wire AC system is universally adopted for generation and transmission of electric power as an economical proposition. However, distribution of electric power is done by 3-phase, 4-wire a.c. system. The underground system is more expensive than the overhead system. Therefore, the overhead system is mostly adopted for transmission and distribution of electric power.
Typical AC Power Supply in a Power System
The large network of conductors between the power station and the consumers can be broadly divided into two parts viz., transmission system and distribution system. Each part can be further sub-divided into two—primary transmission and secondary transmission and primary distribution and secondary distribution. In Fig. 2, the layout of a typical AC power supply scheme in a power system is shown by a single line diagram. It may be noted that it is not necessary that all power schemes include all the stages shown in the figure. For example, in a certain power scheme, there may be no secondary transmission and in another case, the scheme may be so small that there is only distribution and no transmission.
Fig. 2: AC Power Supply in a Power System
For further details, please visit:
No comments:
Post a Comment