The backup protection provides the backup to the main protection during a short circuit whenever it fails in operation or is cut out for repairs. The backup protection is essential for the proper working of the electrical system.
What is purpose of backup protection Mcq?
Backup protection is provided so as to: Increase sensitivity. Increase speed of protection system. To act in case of failure of primary protection.
What is backup protection?
The backup protection is the second line of defence which isolates the faulty section of the system in case the main protection fail to function properly. … The backup protection is mainly used where the main protection of the adjacent circuit is unable to backup the main protection of the given circuit.
What is the purpose of backup protection answer to increase the speed of B to increase the exit C to leave no blind spot D to guard against failure of primary?
Correct answer is option ‘D’.
What is backup protection relay?
Definition of backup relay
: a secondary relay to protect a power system against faults in the event of failure of the primary relay to function as desired.
What is digital protection?
Digital protection is based on the use of computers in power line relaying. … The text covers the mathematical basis of numerical techniques and relay algorithms, the basic elements of digital protection and the fundamentals underlying the commonest algorithmic forms, particularly as applied to line protection.
Why do we need a protection scheme for power system?
The objective of a protection scheme is to keep the power system stable by isolating only the components that are under fault, whilst leaving as much of the network as possible still in operation. The devices that are used to protect the power systems from faults are called protection devices.
What is primary protection and backup protection?
Primary protection (Main protection) is the essential protection provided for protecting an equivalent/machine or a part of the power system. As a precautionary measure, addition protection is generally provided and is called Backup Protection.
What is the difference between primary and back up protection?
The primary protection is the first line of defense and is responsible to protect all the power system elements from all the types of faults. The backup protection comes into play only when the primary protection fails.
What type of backup protection is used for alternators?
Backup protection is provided by distance relays (Device 21) or voltage supervised overcurrent relays (Device 51V). These relays can be connected to CTs at the neutral end of the generator or they can be connected to CTs at the generator terminals.
Which type of backup protection is widely used for protection of transmission line?
Types of Backup Protection:
Relays backup protection: Single circuit breaker is used to for both primary and backup relays. Breaker Backup protection: Separate circuit breakers is used for both protections in the same station.
What is differential protection of generator?
Differential protection for a generator is mainly employed for the protection of stator windings of generator against earth faults and phase-to-phase faults. The stator winding faults are very dangerous, and it causes considerable damage to the generator.
Why do not require any protection against prime mover failure in case of?
We do not require any protection against prime mover failure in case of. turbo-generator sets. … back pressure turbo-generators.