Feeder protection relay is a most common used set of relay which used to make protect cable & lines from overheads and also monitoring the power grid which make sure continually supply of power energy. In case [1] of fault, feeder protections relay help to prevent figure 1 shown below the fault to spread in the health part of the equipment.

Figure 1: Feeder Protection Relay

Whenever feeder relay detect any kind of the fault in the power system then it going to off automatic circuits, so it help to prevent circuits from the overcurrent. It also protect during the higher voltage of current, ground fault, low current & overload etc. Ashida Electronics is one of leading firm in India for electrical protection relay, providing wide range of feeder protection relay with multifunction work.

Switchgear protection is a main component of feeder, Switchgear is a combination of electrical switch which help to make disconnect power system, fuses & circuit breaker. A fuse is also one kind of feeder relay in power system which helps to make protect our electrical equipment during the high voltage, low voltage & overload etc. This kind of electrical device is mainly link with direct power supplier.

Due to improvement in technology, at the end of 19th century high voltage was invested to operating electrical motor and other electrical equipment. In the 20th century technology has been improved over time so we can now use switchgear protection voltage up to 1,000 KV. Mainly switchgear protection has located in the substation on the both for high current & low voltage side of the large power transformer. Or mainly medium voltage of switchgear relay located in the building along with the some function like monitoring, controlling & protecting etc.

The main characteristic of a radial system is that power flow only in one direction, i.e. from the generator or the supply end to the [2] load end. It has the drawback that continuity of supply cannot be controlled at the load end in the occurrence of a fault.

In a radial system when the number of feeders is connected in series as shown in the figure. It is desired that the smallest possible part of the system should be off. This is conveniently achieved by employing time graded protection. The over current system should be adjusted in such a way that the longer the relay from the generating station the lesser the time of operation.

The parallel connection of the supply is mainly used for the continuity of the supply and for sharing the load. When the fault occurs on the protective feeder, the protective device will select and isolate the defective feeder while the other instantly assume the increased load.

One of the simplest methods for the protection of the relay is the time graded overload relay with inverse time characteristic at the sending end and instantaneous reverse power or directional relays.

References:

1. https://www.weeklywoo.com/feeder-protection-relay/#:~:text=Feeder%20protection%20relay%20is%20a%20most%20common%20used,spread %20in%20the%20health%20part%20of%20the%20equipment.
2. https://circuitglobe.com/feeder-protection.html

Cite this article:

Nandhinidwaraka.S (2021) The sources of Feeder Protection Relay, Anatechmaz, pp. 25