When feeder ring distributes energy from two or more than two producti...
Radial Distribution System: This system is used only when substation is located at the center of the consumers. In this system, different feeders radiate from a substation and feed the distributors at one end. Thus, the main characteristic of a radial distribution system is that the power flow is in only one direction. It is the simplest system and has the lowest initial cost but it is not highly reliable.
A major drawback of a radial distribution system is, a fault in the feeder will result in supply failure to associated consumers as there won't be any alternative feeder to feed distributors.
Ring main system: In this system, each distribution transformer is fed with two feeders but in different paths. The feeders in this system form a loop which starts from the substation bus-bars, runs through the load area feeding distribution transformers and returns to the substation bus-bars.
Ring main distribution system is the most preferred due to its following advantages:
1) There are fewer voltage fluctuations at consumer's terminal.
2) The system is very reliable as each distribution transformer is fed with two feeders. That means, in the event of a fault in any section of the feeder, the continuity of the supply is ensured from the alternative path.
Interconnected distribution system: When a ring main feeder is energized by two or more substations, it is called as an interconnected distribution system. This system ensures reliability in an event of transmission failure. Also, any area fed from one generating station during peak load hours can be fed from the other generating station or substation for meeting power requirements from increased load.