Which of the following is the unit type of protection in feeder?
The first protection arrangement is known as a ‘Circulating Current‘ system. The second protection arrangement is known as a ‘Balanced Voltage’ system. The majority of unit protection systems work through the determination of the relative direction of the fault current.
Which of the following is a unit type of protection?
This type of protection system is known as unit protection. Certain types of unit protection are known by specific names, e.g. Restricted Earth Fault and Differential Protection. Unit protection can be applied throughout a power system and, since it does not involve time grading, is relatively fast in operation.
Which of the following is non unit type of protection in a transmission line?
Examples of non-unit protection include fuses, overcurrent and distance relays, reclosers, and sectionalisers.
What is feeder differential protection?
Differential protection The differential feeder protection circuit is derived from the well known Merz-Price circulating current system. … A summation current transformer T1 at each line end produces a single-phase current proportional to the summated 3-phase currents in the protected line.
What is unit differential protection?
• Differential protection is the best technique in protection. In this type of. protection the electrical quantities entering and leaving the protected zone. or area are compared by current transformers (C.T.s).
What is unit system and non protection system?
A unit protective system is one in which only faults occurring within its protected zone are isolated. Faults occurring elsewhere in the system have no influence on the operation of a unit system. A non unit system is a protective system which is activated even when the faults are external to its protected zone.
Which of the following relay is Unit protection relays?
If the relay is used for the protection of faults within a specified device like transformer, generator, motor etc., are called as unit protection relays. Examples: 1. Differential relays 2. Buccholz relays If the fault outside the unit protection area or zone are called through faults.
What is primary protection?
The main protection or primary protection is the first line protection which provides quick-acting and selective clearing of a fault within the boundary of the circuit section or element it protects. The main protection is provided in each section of an electrical installation.
What type of protection does a pilot wire use?
Transmission line protection by pilot wires (pilot relaying) is limited to 30 to 40 km in rout length. For longer transmission lines and subtransmission lines or even distribution feeders, distance protection is used.
What is feeder and its types?
Many types of feeders have been designed some of which are apron, belt, chain, roller, rotary, revolving disc, and vibrating feeders. Apron Feeder: Apron feeders are commonly used to extract or feed heavy bulk materials such as metals and heavy ores.
What are the two methods of feeder protection?
The various methods of protecting the feeders are:
- Over current protection.
- Distance protection.
- Pilot relaying protection.