Directional protection

What is directional protection?
What is directional and non directional protection?
What is directional overcurrent protection?
What are the advantages of directional protection?
Why directional relay is used?
What is the difference between directional and non directional bond?
What is the difference between directional and non directional movement of plant?
What is directional fault?
What is an directional current?
What is a directional relay?
What is directional overcurrent principle?
What is directional and non directional overcurrent protection?
What is directional power?
What is meant by directional discrimination principle?
What is directional protection for parallel feeders?
What is the difference between directional and non directional bond?
What is the difference between directional and non directional movement of plant?
What are the 2 types of overcurrent protective device?

What is directional protection?

Directional protection: protection equipment capable of detecting a fault upstream or downstream (in a given direction) of its position. Earth fault (e/f) protection: protection in which the residual variable (current and/or voltage) is monitored to detect phase-to-earth fault.

What is directional and non directional protection?

In the protection of parallel feeders, non-directional overcurrent relays are used on the source side, and directional overcurrent relay used on the load side.

What is directional overcurrent protection?

Directional overcurrent protection helps to protect the installation against phase-to-phase, phase-to-neutral, and phase-to-earth short circuits with total selectivity. The ANSI 67 - Directional overcurrent protection Digital Module is used to generate either an alarm or a trip.

What are the advantages of directional protection?

Directional protection enables better discrimination of the faulty part of the network than with overcurrent protection. It is necessary to use it in the following conditions: in a system with several sources. in closed loop or parallel-cables systems.

Why directional relay is used?

The directional relays permit tripping only for a certain direction of current flow, and the other relays determine (1) if it is a short circuit that is causing the current to flow, and (2) if the short circuit is near enough so that the relays should trip their circuit breaker.

What is the difference between directional and non directional bond?

Directional bonds are interpreted differently when observed from different sides while non – directional bonds look the same when observed from any side.

What is the difference between directional and non directional movement of plant?

When the movement of a plant is dependent on the direction of stimulus, it is called directional movement. For example, shoot tip grows towards the source of light. When the movement of a plant is independent of the direction of stimulus, it is called non directional movement.

What is directional fault?

Like Directional Overcurrent, Directional Earth Fault (DEF) is used to differentiate between different fault types to ensure that co-ordination between protection devices such as distribution circuit breakers and reclosers is maintained.

What is an directional current?

Unidirectional means that the load current, Ii, only flows in one direction. The gain of this circuit is composed of two parts. First, the sense resistor, R1, converts the load current, Ii, into a voltage based on the value of its resistance. This voltage is called the sense voltage.

What is a directional relay?

Definition: A protection relay in which the tripping decision is dependent in part upon the direction in which the measured quantity is flowing.

What is directional overcurrent principle?

Principle of Directional Overcurrent Relay :

A directional overcurrent relay operates on the same principle as that of an overcurrent relay. But in an overcurrent relay, the driving torque is developed due to the magnetic fields produced by the operating current of the circuit given through a current transformer.

What is directional and non directional overcurrent protection?

Directional over current protection functions are developed to protect the power system from excessive current flowing in an already known direction and voltage-dependent overcurrent protection is used to protect the equipment at predefined voltage levels.

What is directional power?

Directional power protection (ANSI 32) is used where a generator runs in parallel to another generator or a utility. It has two forms, overpower and underpower. Directional Overpower and Underpower protection calculate the total apparent power flow through the recloser based on the voltages and currents.

What is meant by directional discrimination principle?

The 'discrimination principle' based on phase angle comparison between a set of phasors, one of which is used as reference is called 'directional discrimination principle'. Relays with this principle are called directional relays.

What is directional protection for parallel feeders?

The protection of parallel feeder requires to use directional relays and to grade the time setting of relay for selective tripping. There are two feeders connected in parallel from source to load. Both of the feeders have non-directional over current relay at source end. These relays should be inverse time relay.

What is the difference between directional and non directional bond?

Directional bonds are interpreted differently when observed from different sides while non – directional bonds look the same when observed from any side.

What is the difference between directional and non directional movement of plant?

What are the 2 types of overcurrent protective device?

Overcurrent protection devices include circuit breakers and fuses.