Distance protection zones

1. What are zones of distance protection?
2. What is 3 zone distance protection?
3. What is Zone 1 and Zone 2 of distance protection?
4. What is Zone 4 in distance protection?
5. Why is zone 1 set to 80?
6. What is Zone 1 extension distance protection?
7. What are the 4 distance zones?
8. What are different types of distance protection?
9. Why is distance protection used?
10. Why Zone 2 of distance relay covers up to only 50% of the adjacent feeder?
11. What is a distance relay 21?
12. What is protective zone in relay?
13. Which CT class for distance protection?
14. What are different types of distance protection?
15. What do you mean by distance protection?
16. What is first zone of protection?
17. How many types of zones are available?
18. Why is distance protection used?

What are zones of distance protection?

Distance relay is the main protection of power transmission lines and make an important role in power system stabilization if it operates selective and instantaneous. The distance relay measures impedance between relay and the fault point.

What is 3 zone distance protection?

The third zone protection of distance relay serves as a backup for fault on the longest transmission line which is adjacent to the line to be protected. For the accurate detection of fault, its reach setting is curtailed to 100% of the primary line plus 100% of the adjacent longest line.

What is Zone 1 and Zone 2 of distance protection?

Zone 1 is primary protection, hence instantaneous operation • Zone 2 is a overreach zone and hence needs to be delayed. ▫ If errors involved is less, then Zone 2 can trigger for Zone 1 fault of adjacent line. Hence Zone 2 is to be coordinated with Zone 1.

What is Zone 4 in distance protection?

There is one more Zone in modern Distance Relay which is called Reverse Zone or Zone-4. As the name Reverse Zone implies it is back-up protection of the Substation where Distance Relay is installed, in our case to the substation A. The setting for zone is normally 10% of the impedance of protected line.

Why is zone 1 set to 80?

As we discussed in the previous video, Zone 1 is set at 80% of the line to compensate for any CT accuracy and calculation errors, and Zone 2 will protect the other 20% of the line with a 20-cycle time delay.

What is Zone 1 extension distance protection?

Zone-1 is meant for protection of the primary line. Typically, it is set to cover 80% of the line length. Zone-1 provides fastest protection because there is no intentional time delay associated with it. Operating time of Zone-1 can be of the order of 1 cycle.

What are the 4 distance zones?

The size of this area varies with situations and contexts. Hall (1969) delineated four zones of interpersonal distance that characterize Western culture: intimate (up to 18 inches), personal (18–48 inches), social (48 inches to 12 feet), and public (greater than 12 feet).

What are different types of distance protection?

These are impedance, reactance, admittance, or mho type relays.

Why is distance protection used?

Distance protection schemes are commonly employed for providing the primary or main protection and backup protection for AC transmission line and distribution line against three-phase faults, phase-to-phase faults, and phase-to-ground faults.

Why Zone 2 of distance relay covers up to only 50% of the adjacent feeder?

Zone 2: Mainly intended to cover the remaining 10 % to 20 % of the Protected Line and provide Backup for the Adjoining Lines (50% of the Adjoning Length). It set to cover Remote End Busbar and Hence it is called as an Overreaching Element.

What is a distance relay 21?

The goal of a distance relay (ANSI/IEEE code 21) is to trip its circuit breaker(s) if a fault occurs within its programmed “reach” and to ignore both normal operating loads and faults lying outside its reach.

What is protective zone in relay?

The zone is defined to include the power system component that has to be protected and include the circuit breakers needed to disconnect the component from the rest of the system.

Which CT class for distance protection?

The PS class CTs are used for differential protection. The differential protection is also called the zone or unit protection.

What are different types of distance protection?

These are impedance, reactance, admittance, or mho type relays.

What do you mean by distance protection?

Distance Protection is a Non-unit System of Protection, which measures the Impedance between the Relay Location and the point where the fault is incident and compares it with the Set Value. If the measured Impedance is less than the Set Value , the Relay operates and Isolates the Faulty Section.

What is first zone of protection?

The protected zone of the first unit called the first zone of protection. It is a high speed unit and is used for the primary protection of the protected line. Its operation is instantaneous; about 1 to 2 cycles. This unit is not set to protect the entire line to avoid undesired tripping due to overreach.

How many types of zones are available?

The world is sometimes divided into five zones according to latitude. The tropical, or Torrid Zone, lies near the Equator and extends to the Tropic of Cancer in the north and the Tropic of Capricorn in the south. The north and south frigid zones (also known as the Arctic and the Antarctic) lie near the poles.

Why is distance protection used?

Distance protection schemes are commonly employed for providing the primary or main protection and backup protection for AC transmission line and distribution line against three-phase faults, phase-to-phase faults, and phase-to-ground faults.