Primary distribution system, Secondary distribution system

in this article we will know about the primary distribution system, we will also studied about the main primary distribuiton system . we will also know about the secondary distribution system.

Primary distribution system

primary distribution system, types of primary distribution system
Primary distribution system is of four types-
1. Radial feeder
2. Parallel feeder
3. Loop feeder
4. Primary network

1. Radial feeder

Radial feeder system is main types of primary distribution system
This feeder is used to supply small and medium residential, commercial loads. It radiates from the secondary substation and branches into sub feeder and laterals which extended into all parts of service area. The feeder and sub feeder are three phase three wire circuit. The distribution transformer is connected to primary   feeder, sub feeder and laterals through fused cutouts.

2. Parallel feeder

It consists of duplicate feed system having two radial feeders running in parallel. Each feeder supplies about half of total load of the area but has a capability to supply the entire load in the event of an outage on the other feeder. Failure of any feeder will result interruption of service until the load normally supplied by the faulted feeder is transferred to the other feeder by automatic control switch.

3. Loop feeder

A system of two or more radial feeders originating from the same or secondary different substation and separately routed through load area is known as loop feeder.it is also main types of primary distribution system.
If ends of two feeders are tied together through normally open switching device the resulting arrangement is known as open loop system and if ends are tied together by means of normally closed switching device the result is a ring loop feeder.

4. Primary Network

This system consists of a number of interconnected feeders. Two or more secondary transmission circuit supply two or more secondary substations from which the feeder takes off. Because the feeder is interconnected power is supplied to all the distribution transformers even though a part of network may be out of service. Each secondary substation consists of a transformer and the necessary switch gear to isolate the faulty feeder and to control feeder.
Secondary distribution system
The secondary distribution system consist of three phase four wire 400V distributors laid along road sides. The service connection are tapped off the off the distributors at convenient points. These connection may be 1 phase two wire circuit or 3 phase 4 wire circuit.These are basic types of primary distribution system.

Secondary distribution system

The secondary system used are-

1. Radial
2. Open loop
3. Network distribution

1. Radial system

It takes off from the distribution transformer and runs through the area to be served by it.

2. Open loop system

This system consist of two distributors taking off from the same distribution transformer and running in different directions and supplying different areas at time of fault one of distributors, power can supplied through partially, from the other distributor.

3. Network distribution

A network grid system consist of a number of inter connected distributors. Two or more distribution transformers feed the distribution network and operate continuously in parallel. This system is suitable for serving high load density metropolitan areas. Which are shows in secondary distribution system.


 Hence these are primary distribution system. if you will find any incorect above article please comment below in comment box.

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