This technical report refers to the electrical protection of all 132kV switchgear. These settings may be re-evaluated during the commissioning, according to actual and measured values. Protection selectivity is partly considered in this report and could be also re-evaluated. Names of parameters in this calculation may differ from those in the appropriate device.

Technical Data of the Lines

Main Line
Conductor TypeACSR Lynx
Length27.8 km
TypeZM Type Tower
Positive sequence impedance 0.1583 + j0.4004 (0.431 ∠68.4°) Ω/ km
Zero sequence impedance0.3246 + j1.228 (1.27 ∠75.2°) Ω/ km
Current capacity (A)487
Next Line
Conductor TypeACSR Lynx
Length36 km
TypeZM Type Tower
Positive sequence impedance 0.1583 + j0.4004 (0.431 ∠68.4°) Ω/ km
Zero sequence impedance0.3246 + j1.228 (1.27 ∠75.2°) Ω/ km
Current capacity (A)487
SEL 311 – Line Protection

Protection Settings Calculations for Lines

SEL-311C Distance Protection Settings
Distance Zone
Non-Homogeneous Correction Angle
Load Impedance and Load Encroachment
Power Swing Detection/ Out of Step Detection
Switch on to Fault (SOTF)
Fuse failure scheme OR Loss of Potential (LOP)
SEL-351A Back-up Over Current Settings
Back up over current settings

Technical Data of the Power Transformers

Transformers – 1
Type of cooling ONAN / ONAF
Vector Group Dyn11
Rated Voltage HV V 132000
Rated Voltage LV (V) 11500
Full Load current HV ( A) 87.48 / 113.72
Full Load current LV (A) 1004.12 / 1305.35
Rated Power ( MVA) 20 / 26
% impedance at the normal tap (12 no.) 10.15% / 13.20 %
Type of tap changer On load
the voltage at the maximum tap (V) 145200
Voltage at the minimum tap (V) 118800
Transformers – 2
Type of cooling ONAN / ONAF
Vector Group Dyn11
Rated Voltage HV (V) 132000
Rated Voltage LV (V) 11500
Full Load current HV ( A)43.7 / 56.9
Full Load current LV (A) 502 / 652.7
Rated Power ( MVA) 10 / 13
% impedance at the normal tap (12 no.) 10.15% / 13.20 %
Type of tap changer On load
The voltage at the maximum tap (V) 145200
Voltage at the minimum tap (V) 118800
SEL-787 Transformer Protection Relay

Protection Settings Calculations for Power Transformers

SEL-787 Transformer Differential Protection
Differential Pick-up
Slope-1 Setting
Slope-2 Setting
Differential Unrestrained (U87P (Un-restrained Differential Pick-up) )
2nd HARMONIC
5th HARMONIC

SEL-351A Transformer HV Over Current
Pick-up Setting
51PP (for phase fault element)
51GP (for earth fault element)
Time Multiplier Setting

SEL-551C Feeder Over-Current and Earth Fault

11kV Outgoing Protection Settings

SEL-551C LT Over-Current and Earth Fault
CDG21 LT Neutral Standby AC series Earth Fault

61 Replies to “Relay Settings Calculations”

  1. avatar

    I need transformer differential protection in micom and siemens siprotec relay

        1. avatar

          thanks for your comment

  2. avatar

    i am looking at REM 615 – motor protection relay setting calculations, stuck up at relay/motor curve (hot/cold)?

    1. avatar

      on your email

  3. avatar

    Please share some relay setting calculations excels ,pdf or doble or RIO test kit calculation files if you have any so that we could purchase it on this website ?

    THANKS …

  4. avatar

    sir
    please share calculation sheet of GE D60 and SEL Distance elay.

    1. avatar

      do not have sheet of GE D60 and SEL Distance relay

      1. avatar

        SIR
        I need line protection calculation 21/21G calculation sheet

  5. avatar

    Dear Sir,
    I need line protection calculation (21/21G) using SEL-311c
    Thanks!

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      please check your email

      1. avatar

        Please share relay calculation excel sheet

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          kindly check ur email for Relay Settings Calculations / Helpful Excel Spreadsheets for Protection Engineers

  6. avatar

    HOW CAN I DOWNLOAD?

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  7. avatar

    I need protection grading, Simulation excel, for 33/11kV voltage level protection . OC (IDMT + HIGH STAGE) AND EF (same as OC) only.. please help.

    1. avatar

      cant download from this page.. please help…

      1. avatar

        has been sent to ur email pls check for Relay Settings Calculations

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  8. avatar

    Sir,

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    1. avatar

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  9. avatar

    Could you please send me a copy of the PDF thank you.

    1. avatar

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  10. avatar

    Dear sir, kindly share relay settings excel sheet

  11. avatar

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    1. avatar

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  12. avatar

    Please share relay calculation excel sheet

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  13. avatar

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  14. avatar

    Dear Sir
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    1. avatar

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  16. avatar

    Sir,

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    1. avatar

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  19. avatar

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  21. avatar

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      Details have been sent to your email with subject: Relay Settings Calculations / Helpful Excel Spreadsheets for Protection Engineers

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    Please share relay calculation excel sheet.
    Relay Settings Calculations / Helpful Excel Spreadsheets for Protection Engineers

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  23. avatar

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    1. avatar

      This product is free for our customers only, and unfortunately, your email is not on our customer list. You can buy any of our training packs (DIGSI 4, DIGSI 5, IEC 61850, ETAP, PSCAD, …), then you can access our free files.

  25. avatar

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    1. avatar

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  26. avatar

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      please check your email for detail