What is the function of restraining coil in differential
relay? as well as restraining current?
- 8 Answers
- 43539 Views
- Medical, Siemens, I also Faced
- E-Mail Answers
Answers were Sorted based on User's Feedback
restraining coils are used in the relay for controlling the
sensitivity characteristic of the relay. Differential
relays are highly sensitive relays. restraining coils
prevents the unwanted tripping of the transformer due to
the spill current due to CT saturation effect, or due to
the mismatch current due to CT characteristic.
| Is This Answer Correct ? | 85 Yes | 3 No |
The concept is simple. In any relay there are two forces namely controlling and deflecting force. Controlling force is responsible for the normal operation of the relay that is during normal current flow (during non faulted conditions). Whenever a fault occurs as we know that the impedance will get reduced and hence the fault current raises above the rated value and flow through the secondary of the CT connected to the relay circuit. Actually both the forces are present during normal operations also. But during fault due to the high fault current the deflecting force raises above the controlling force thus actuating the relay operation. Controlling force is created by the restraining coil and the deflecting force is created by the operating coil. This force production is as simple that it is based on the fact that a current carrying coil experiences a force.
| Is This Answer Correct ? | 15 Yes | 6 No |
Answer / m raviteja
the function of the restraining coil is to avoid the mal
fuctioning of the main relay. restraining current is
flowing through the restraining coil is to prevent the
external faults. the increase the current increase the
restraining torque.
| Is This Answer Correct ? | 11 Yes | 4 No |
Answer / arvind manavazhagan
The concept is very simple. If we consider any relay there are two forces namely controlling and deflecting force.Both the forces are present during normal operation also. Controlling force keeps the contacts of a relay in normal position during normal operating conditions.When a fault occurs we know that due to a reduced impedance high fault current may flow through the circuit and hence through the secondary of the CT that is connected to the relay also.This in turn increases the deflecting force than the controlling force thus operating the relay.Controlling force is produced by the restraining coil and deflecting force is produced by restraining coil.
| Is This Answer Correct ? | 6 Yes | 2 No |
Answer / madivalanagaraja@gmail.co
T the bias force produced due to the restraining coil greater than the operating force produced by the operating coil is relay is inoperative. When the internal fault occurs, the operating force becomes more than the bias force. Due to this, Beam moves and the trip contact sir closer to open a circuit breaker
| Is This Answer Correct ? | 2 Yes | 0 No |
Answer / vikash kumar barnwal
restraining coil is given to avoid mal-functioning of differential relay.
since differential relay works on the principle of balancing the incoming and outgoing currents from alternator coils and due to the inductive effect of alternator coils, there is some phase angle difference between these currents..
so even there is no fault it may cause to operate the relay coil.
hence, restraining coil is given to limit the sensitivity of the differential relay.
| Is This Answer Correct ? | 0 Yes | 1 No |
Answer / tarun singh
restraining coil is used to avoid the trouble arising due to
difference in ct ratios..
| Is This Answer Correct ? | 3 Yes | 8 No |
Answer / gunasekaran
restaining coil is used for restaining the 2nd and 5th
hormonics in inrush current
| Is This Answer Correct ? | 5 Yes | 18 No |
Explain in brief description about the operation of DG sets.
why ahould you show client/engineer activities clearly on the project plan
List out the different frequency domain specifications?
What is the role of the 50 STUB protection at a GIS 400KV substation with SIEMENS protection relays?
1)What will you do if main incomer VCB fail in your site ?
what is alluminium arm in ab conductors
Main advantage of auto transformer over two windings transformer is that A it needs no cooling B it uses only one winding C core losses are reduced D it has simple construction
How much ph is maintained of water electrolyte which is used in LRS for 1200 kw slipring induction motor ?
0 Answers AMS, JK Lakshmi Cement,
Give me clear explanation.What is the Different Between Load break switch and Vacuum circuit breaker
which is chemical used as in ro water what is difference betweeen multi grade filter&dual media filter
What is the function of the exiter in DG.
which type of breaker sould be used for different level of voltage ? (i.e at 11 Kv, 33 Kv, 66 Kv....
-
Civil Engineering (5085) - Mechanical Engineering (4451)
- Electrical Engineering (16632)
- Electronics Communications (3918)
- Chemical Engineering (1095)
- Aeronautical Engineering (239)
- Bio Engineering (96)
- Metallurgy (361)
- Industrial Engineering (259)
- Instrumentation (3014)
- Automobile Engineering (332)
- Mechatronics Engineering (97)
- Marine Engineering (124)
- Power Plant Engineering (172)
- Textile Engineering (575)
- Production Engineering (25)
- Satellite Systems Engineering (106)
- Engineering AllOther (1379)
