Notes on electrical power generation, transmission and distribution

Ring main distribution system

The drawback of radial electrical power distribution system can be overcome by introducing a ring main electrical power distribution system. Here one ring network of distributors is fed by more than one feeder.

In this case if one feeder is under fault or maintenance, the ring distributor is still energized by other feeders connected to it. In this way the supply to the consumers is not affected even when any feeder becomes out of service.

In this way, supply to the consumers connected to the healthy zone of the ring, can easily be maintained even when one section of the ring is shutdown. The number of feeders connected to the ring main electrical power distribution system depends upon the following factors.

Factor #1 – Maximum demand of the system: If it is more, then more numbers of feeders feed the ring.

Factor #2 – Total length of the ring main distributors: If it length is more, to compensate the voltage drop in the line, more feeders to be connected to the ring system.

Factor #3 – Required voltage regulation: The number of feeders connected to the ring also depends upon the permissible allowable, voltage drop of the line.

Sometimes, instead of connecting service main directly to the ring, sub distributors are also used to feed a group of service mains where direct access of ring distributor is not possible.

Interconnected system

In this type of system two to more than two generating station or substation are energizing the feeder ring. In this system any area from one generating station during peak load hours can be fed from other generating station which increase the efficiency of the system.

Now a days electrical energy is generated, transmitted and distributed in the form of A.C. But for certain applications D.C. supply is necessary.

The D.C. Supply from the substations fed to the load through distributors.