Distribuiton System

Distribution of Power -image
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Large amount of power is generated at the generating stations. Nowadays bigger size of alternators are used to generate large amount of power to cater the required increasing demand and also future requirements. It is difficult to build generating station near the consumption centres due to safety reasons, social issues and environmental issues. Thus, it is necessary to transfer bulk of electrical power through longer distances. This part of power system distributes electrical for local utilization.
Electrical Power distribution is defined as, "the component of an electrical power system connecting all the consumers in an area to the bulk power sources." or it can be also defined as the system between the substation fed by the transmission system and the consumers meter (energy meter). Bulk power stations are connected to generating station by transmission lines. They fed number of substations.
A substation distributes the power to domestic, commercial and industrial consumers.

Distribution system consists of:-

Schematic Diagram of  Distribution System
Schematic Diagram of  Distribution System

  1. Sub-transmission circuits of voltage rating in between the range 33kV to 220kV which deliver electric power to distribution substation. This transmission circuits are called feeders. Feeder connects the substation to where the power is to be distributed. 
  2. In distribution substations, the transmission voltages (33kV or sometimes 66kV) is stepped down to 11kV by using step down transformer for power distribution to load points through distribution networks.
  3. At these load points, a distribution transformer is usually installed on poles near the consumers' site which transform (step down ) the primary voltage to uitlisation voltage 230/415 V.
  4. Distributor:- A distributor is a conductor from which tappings are taken for power supply to the consumers of different types according to the need (domestic, commercial, industrial etc).
  5. Service mains:- Service mains or service lines are generally a small cable which deliver the energy from the distributor to the consumer's premises/terminals.