what is STUB protection in tranmission system and switch
yard area?

Answer Posted / abdelrahman hussein

The stub bus element protects for faults between two breakers in a breaker-and-a-half or ring bus configuration when the
line disconnect switch is open. At the same time, if the line is still energized through the remote terminal(s), differential
protection is still required (the line can still need to be energized because there is a tapped load on a two-terminal line or
because the line is a three-terminal line with two of the terminals still connected). Correct operation for this condition is
achieved by the local relay sending zero current values to the remote end(s) so that a local bus fault does not result in
tripping the line. At the local end, the differential element is disabled and stub bus protection is provided by a user-selected
overcurrent element. If there is a line fault, the remote end(s) trips on differential but local differential function and the DTT
signal (if enabled) to the local end are blocked by the stub bus logic, allowing the local breakers to remain closed.

Is This Answer Correct ?    7 Yes 0 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

Why the magneti fields are not passes from southpole to north pole

1647


plz tel me syllabus and exam date 4 jr executive engg (electrical)

1497


star delta starter contorl circuit... drawing..

1670


How to decide no. of Step and Kvar for APFC Panel 40 kvar MD: 33.12 KVA Avg pf : 0.8540

671


What is Harmonics how it is produced and what is the method to control the same

1774






10 tube light connect in mcb breaker.one tube light is fault.so breaker is tribe.how fault is rectified.(using 3wire phase,earth,neutral)

2157


How many types of interlocking use in screw type air compressor,make-Kaser(BSD MODEL)?

1605


what are the difference between PLC and embedded

1653


at work we have a 3 phase motor but on testing one phase isnt getting a reading. it runs 24 hours a day all week. stops and starts well no noise or heating. the phase isnt down to earth.is it just a bad meter reading or not? phases one and three came up with a resistance reading of 0.4 but phase 2 couldnt get anything shows up as open circuit.

1184


whats the existence of reactive power and when it arises?

1632


what is cause of static electricity? I experience shock when i touch metal equipment in a room ,furher check shows earth leakage showing 80ma at the DB near to the 400 MCCB?

1460


I have motor 1500 HP and , 4160 V , 60 HZ , then i need the rating of transformer which can feed that motor ??

1405


How to select batteries required for ups and the inverter if we Known load? And how AH is selected of battery?

892


Briefly describe your ideal job?

2566


how make megger test for control cable like 12c x 1.5mm and what it apply voltage and test timing details.

1766