Feeders Protection Schemes

8/3/2019 Feeders Protection Schemes

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Feeders Protection Schemes.

2 - Transformers Protection Schemes.

3 - Bus Bar Protection Schemes.

4 - Generators Protection Schemes.

Types and voltage level of Feeders

A O. H. T. Lines

500 KV O. H. T Line

400 KV O. H. T Line

275 KV O. H. T Line

220 KV O. H. T Line

132 KV O. H. T Line

66 KV O. H. T Line

33 KV O. H. T Line

22 KV O. H. T Line

11 KV O. H. T Line

B U. G. Cables

275 KV U. G. Cable

220 KV U. G. Cable

132 KV U. G. Cable

66 KV U. G. Cable

33 KV U. G. Cable

11 KV U. G. Cable



500, 400, 275 and 220 KV O.H.T. Lines

Protection Schemes

Main (A) Protection:

Distance Protection Permissive Over Reach Scheme. (POTT)

Main (B) Protection:

Distance Protection Permissive Under Reach Scheme. (PUTT)

Backup Protection:

I.D.M.T Directional O/C & E/F Relay.

Circuit Breaker Fail to Tripe.

Inter Trip.

SF6 Pressure Low Trip

Cable Oil Pressure Low Trip (For Cable Tail )

Drawing : single Line diagram for

protection scheme Click Here

132 and 66 KV O.H.T. Lines

Protection Schemes

Main Protection:

Distance Protection Permissive Under Reach Scheme. (PUTT)

Back up Protection:


Circuit Breaker Fail To Tripe.

Inter Trip.


Cable Oil Pressure Low Trip (For Cable Tail)





33 and 22 KV O.H.T. Lines

Protection Schemes

I.D.M.T Direction O/C & EF Relay

I.D.M.T Non Direction O/C & EF Relay

11 KV O.H.T. Lines

Protection Schemes

I.D.M.T Direction O/C & EF Relay

275, 220 U.G.C. Line

Protection Scheme


Differential Protection (Solkor R)

Main (B) Protection:

Distance Protection Permissive Over Reach Scheme. (POTT) With Carrier Signal through Pilot Cable

Back up Protection:


Circuit Breaker Fail to Tripe

Inter Trip.


Cable Oil Pressure Low Trip



132, and 66 KV U.G.C. Line

Protection Scheme

Main Protection:


Back up Protection:


Circuit Breaker Fail to Tripe.

Inter Trip (Through Pilot Cable).


Cable Oil Pressure Low Trip

33, 22 KV U.G.C. Line

Protection Scheme

Main Protection:


Back up Protection:


I.D.M.T Non Directional O/C & E/F Relay.

Cable Oil Pressure Low Trip.

11 KV U.G.C. Line

Protection Scheme

Main Protection:


Back up Protection:

I.D.M.T Non Directional O/C & E/F Relay.



Some types of power transformers

300 MVA. 3 Winding Power Transformer

275 KV / 132 KV / 33 KV. (Y.Y.).

75 MVA. & 45 MVA. 2 Winding Power Transformer 1

32 KV / 33 KV.

30 MVA 2 Winding Power Transformer

132 KV / 11 KV.

20 MVA & 15 MVA 2 Winding Power Transformer

33 KV / 11 KV.



300 MVA 3 Winding Power Transformer

Protection Scheme.

Main (A&B) Protection:

1. Differential Protection.

2. Restricted Earth Fault Protection. (both at 275 kv and 132 kv)

side neutral of the star winding.

BackupProtection:

C.B Fail to trip.

I.D.M.T Non Direction O/C & E/F relay on 300 KV side

I.D.M.T Direction O/C & E/F relay on 132 KV side

Inter Trip (through pilot cable).

Buchhols Trip.

Tap Changer Buchhols Trip.



Oil Temperature Trip.

Winding Temperature Trip.

Cable oil pressure Low Trip. (for cable tails )

SF6 pressure Low Trip.

75, 45 And 30 MVA- 2 Winding Power Transformer

Protection Scheme.



2. Restricted Earth Fault Protection.

(At the neutral of the LV. Winding).

Backup Protection:

Stand-By Earth Fault relay at the neutral of LV. Winding.

C.B Fail to trip. (For 132 KV. C.B only)



Buchhols Trip.

Tap Changer Buchhols Trip.


Cable oil pressure Low Trip. (For cable tails)

20 & 15 MVA- 33 / 11 KV, 2 Winding Power Transformer

Protection Scheme.





2. Restricted Earth Fault Protection.

(At the neutral of the LV. Winding).

Backup Protection:

Stand-By Earth Fault relay at the neutral of LV. Winding.



Buchhols Trip.

Bus-Bar Protection Schemes.

500, 400, 275, 220 and 132 KV. Bus-Bar Protection Scheme.

- Differential Protection For each section of bus-bar.

- SF6 Pressure low Trip.

66 and 33 KV. Bus-Bar Protection Scheme.

- Differential Protection For each section of bus-bar or Arc protection or Micro switch protection.

- SF6 Pressure low Trip.

22 and 11 KV BUS-Bar Protection Scheme.

- Arc protection or Micro switches protection.

500, 400, 275, and 220 KV BB section & BB couplers protection scheme.

- I.D.M.T Non Directional O/C & E/F Relay.

- C.B Fail to Trip.

- SF6 Pressure Trip.



- Inter Trip (through pilot cable).

132 KV BB section & BB couplers protection scheme.


- C.B Fail to Trip.





Shunt Reactor Protection Scheme.

275 &132 KV. Shunt Reactor Protection Scheme.

I.D.M.T Non Direction O/C & E/F relay.

Inter Trip (through pilot cable SHR connected through cable C.B. for 132 kV only).

Buchhols Trip.



Cable oil pressure Low Trip. (For cable tails)

SF6 pressure Low Trip.

C.B Fail to trip. (For 132 KV. C.B only).

33 KV. Shunt Reactor Protection Scheme for both connected

to 33 KV Bus-Bar or to tertiary of 300 MVA Transformer.



I.D.M.T Non Direction O/C & E/F relay.

Buchhols Trip.



Documents

Feeders Protection Schemes