Protection Scheme

1 - 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:

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

  2. Circuit Breaker Fail to Tripe.

  3. Inter Trip.

  4. SF6 Pressure Low Trip

  5. 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:

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

  2. Circuit Breaker Fail To Tripe.

  3. Inter Trip.

  4. SF6 Pressure Low Trip

  5. Cable Oil Pressure Low Trip (For Cable Tail)

      Drawing : single Line diagram for
          protection scheme Click Here
 

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

•     Main (A) Protection:
Differential Protection (Solkor – R)

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

•     Back up Protection:

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

  2. Circuit Breaker Fail to Tripe

  3. Inter Trip.

  4. SF6 Pressure Low Trip

  5. Cable Oil Pressure Low Trip

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

•     Main Protection:
Differential Protection (Solkor – R)

•     Back up Protection:

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

  2. Circuit Breaker Fail to Tripe.

  3. Inter Trip (Through Pilot Cable).

  4. SF6 Pressure Low Trip

  5. Cable Oil Pressure Low Trip

33, 22 KV U.G.C. Line
Protection Scheme

•     Main Protection:
Differential Protection (Solkor – R)

•     Back up Protection:

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

•     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:
Differential Protection (Solkor – R)

•     Back up Protection:

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