Types of Distribution System

 

There are following types of distribution system.

• Radial system
• Ring main system
• Interconnected system

Radial distribution system

• Figure shows radial distribution system. One feeder PQ is radiate out from the substation. 
• It feeds distributor from one end only. 
• The distributor is fed at point A and terminates at point D. 
• It means that the load is given at first consumer A and last consumer D.
• Obviously, the last consumer gets less voltage due to voltage drop in the distributor.

Advantages

• Simple distribution system
• Less initial cost

Disadvantages

• When a fault occurs on distributor, power supply is completely interrupted at fault point to all the consumers
• Consumer at far end gets reduced voltage
• If the distributor is extended for future load, the voltage drops increase

Ring distribution system

• It is a distributor in the closed loop and fed at one or more point. 
• Such a distributor starts from one point and makes loop through area and finally returns to the same point. 
• The distributor can be considered as series of open distributors fed at both ends.
• The ring distributor feeding from one point is shown in the figure. 
• Here P is feeding point and PQRSTUVWP forms closed loop for feeder. The tapings for the distributor is taken from point R, T and V respectively. 
• The distributors A, B and C are shown in the figure. 
• It is equivalent to straight distributor fed at both ends with equal voltage for the calculation purpose.

Advantages

• Less copper requires than the radial system
• Less fluctuation of voltage at consumer’s end
• Reliability increases, if the fault occurs at point, the power supply are maintained from other point.

Interconnected distribution system

• When the ring feeder is energized through two or more than two generators / substations, it is called as interconnected system. 
• Figure shows two substations S1 and S2 which feeds feeder PQRSTUVWP. 
• If there is fault between feeders RS, the feeder Q and R receives power through substation S1 and feeder S receiver power through substation S2.

Advantages

• Service reliability increases
• Good voltage regulation is achievable
• Peak load can be fed from the other substation and this will reduces the reserve generating capacity

You may also like :

Compare – Transistor & SCR

Compare – Audio Amplifier & Tuned Amplifier

Compare – Intrinsic Semiconductor & Extrinsic Semiconductor

Compare – SCR & Asymmetrical SCR