The function of protective relaying is to cause the prompt removal from service of any element of a power system when it suffers a short circuit, or when it starts to operate in any abnormal manner that might cause damage or otherwise interfere with the effective operation of the rest of the system.
Why is protective relaying and breaker coordination important in the electrical system?
Actually circuit breaker isolates the faulty system from rest of the healthy system and this circuit breakers automatically open during fault condition due to its trip signal comes from protection relay. …
Why protection is important in power system?
The main objective of using power system protection is to detach the faulty section from the system to make the rest of the portion work without any disturbance. In addition to this, it is used for the protection of power system and prevent the flow of fault current.
What is the major drawback of using SF6 circuit breakers?
Disadvantages of SF6 circuit breakers:
The internal parts need cleaning during periodic maintenance under a clean and dry environment. A special facility requires transportation and the maintenance of the quality of gas. SF6 gas is suffocating to some extent.
What is purpose of backup protection?
The backup protection provides the back up to the main protection whenever it fails in operation or its cut out for repairs. The backup protection is essential for the proper working of the electrical system.
Which relay is used in transformer?
Relays for Transformer Protection
|SL||Voltage Ratio and Capacity of Transformer||Common Relays|
|9||400/220KV 315MVA||Differential Relay Overflux Relay Buchholz Relay OLTC Buchholz Relay PRV Relay OT Trip Relay WT Trip Relay Over Load (Alarm) Relay|
What are the good features of protective relaying?
In order that protective relay system may perform this function satisfactorily, it should have the following qualities :
What are the types of protection relays?
Basic classification of protective relays includes:
- Electromagnetic Relays: Armature. Induction cup / induction disc.
- Static Relays: Analog input signals are processed by solid state devices.
- Digital / Numerical Relays: Uses programmable solid state devices based on digital signal processing.
Why are isolators installed?
An isolator switch can be fitted between your meter and fuse board, allowing connection or disconnection of your electricity supply without the need of a Distribution Network Operator, and ensuring the circuit is safe and de-energised to allow maintenance work to take place.