What are the two types of protection given for busbar?
18.9. 4). This type of busbar protection has two types: low-impedance biased differential protection and high-impedance differential protection, as described here.
What does busbar protection require?
To maintain system stability, the primary objective of busbar protection is to limit damage and remove busbar faults before back-up line protection. A low impedance differential system used to have a relatively long operation time.
What are the most commonly used scheme for the bus protection?
The most commonly used schemes for bus-zone protection are: 1. Backup Protection for Bus-Bars 2. Frame Leakage or Fault-Bus Protection 3. Differential Overcurrent Protection.
How is a bus bar protected?
Busbar protection is a protection scheme meant to protect the busbar from electrical fault. Various feeders are connected to a busbar through circuit breaker in any of the bus configuration viz. Under this case, the generator power will be evacuated through busbar by Feeder-3&4. Thus the generator will remain stable.
Which relay is used in differential protection?
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.
How many relays are needed for busbar differential protection?
Low-Impedance Bus Differential Protection— Provide flexible low-impedance bus differential protection for various busbar topologies and sizes. You can protect systems with up to 21 three-phase bus terminals by using three relays to provide 6 three-phase differential bus zones and 3 independent check zones.
How are differential relays provided in breaker and half scheme?
Two differential relays are provided for each T-Section by summating the three concerned CTs i.e. CT1, CT2, and CT5 for T-Section of feeder-1 and CT3, CT4 and CT5 for T-Section of feeder-2. The CTs arrangement is shown in the figure for 4 CTs method in breaker and half scheme:
How are differential relays used in Teed protection?
Teed Protection will be used to cover the blind area between bus CTs, Line CTs, and Tie Breaker CT. Two differential relays are provided for each T-Section by summating the three concerned CTs i.e. CT1, CT2, and CT5 for T-Section of feeder-1 and CT3, CT4 and CT5 for T-Section of feeder-2.
What are the principles of a busbar protection scheme?
This is a unit type of protective scheme in which the currents entering and leaving the busbar installations are compared continuously. The objective is to provide fast operation at a low fault setting for internal faults and yet retain stability up to the highest possible value of short circuit current on through faults.