What is the function of differential protection relay?
One of the most important protection in power system is differential protection. It is used to protect the electrical equipment against internal fault such as internal winding short circuit or bus bar phase to phase short circuit, inter turn short, winding puncture etc.
Where is differential relay used?
Generally, differential relays are used to protect the equipment against internal faults. Merz price protection scheme is one form of the differential relay which is used to protect the stator winding of Alternator from the internal faults. Differential relay is also used for the protection of transformer winding.
What is the principle of differential relay?
Definition: The relay whose operation depends on the phase difference of two or more electrical quantities is known as the differential protection relay. It works on the principle of comparison between the phase angle and the magnitude of the same electrical quantities.
What are features of differential relay?
The relay shows clearly the characteristics of three-phase differential protection. This includes high stability during ‘out-of-zone’ faults, zero-sequence current filtering for each winding, high-speed operation, magnetising inrush restraint, amplitude and vector matching.
Why do we need protection relays?
The purpose of the protection relay is to detect a problem, ideally during its initial stage, and to either eliminate or significantly reduce damage to personnel and/or equipment. A protection relay can also be used to provide additional protection by detecting the fault contributors (overheating, overvoltage, etc.)
What is differential protection scheme?
Differential protection is a unit-type protection for a specified zone or piece of equipment. It is based on the fact that it is only in the case of faults internal to the zone that the differential current (difference between input and output currents) will be high.
What are the three types of relay?
The three main types of relays are electromechanical, solid-state, and reed.
What are the 5 applications of relay?
Applications of Relays in Electronic Circuits
- Relay Drive by Means of a Transistor.
- Relay Drive by Means of SCR.
- Relay Drive from External Contacts.
- LED Series and Parallel Connections.
What is the two types of percentage differential relay?
Types of Percentage Differential Relay Three terminal system application of the percentage differential relay. Induction Type biased Differential Relay.