Protection must be sufficiently sensitive to operate reliably under minimum fault conditions for a fault within its own zone while remaining stable under maximum load or through fault conditions. A relay should be able to distinguish between a fault and an overload.
What are the essential qualities of protective relaying explain?
Such an essential qualities of protective relaying are: Reliability, Selectivity and Discrimination, Speed and Time, Sensitivity, Stability, Adequateness, Simplicity and Economy.
What are basic requirements of protection system?
The following are the basic requirements of any power system protection system: Reliability. Simplicity. Selectivity.
What are the main features of good protective system?
The protective system should be sensitive that it should operate for low values of fault current. (ii) Selectivity. The protective system should select correctly the faulty part of the power system and disconnect the same without disturbing the rest of the system. (iii) Reliability.
Why is speed of protection so important?
Speed of operation is the ability of the protection system to operate in a short time after fault inception. Fast operation is important in preserving system stability, reducing equipment damage, and improving power quality.
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.
What is need for protection?
Objective of Power System Protection: 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 purpose of protection system?
Primary function of the protective system is to detect and isolate all failed or faulted components as quickly as possible, thereby minimizing the disruption to the remainder of the electric system.
What are the functions and necessity of protection?
Protection on the transmission and distribution system serves two functions: protection of plant and protection of the public (including employees). At a basic level, protection disconnects equipment which experiences an overload or a short to earth.