Transformers are valuable equipment which make a major contribution to the supply security of a power system. Optimum design of the transformer protection ensures that any faults that may occur are cleared quickly and possible consequential damage is minimized. Following Protection functions can be used to protect Transformers.

  • ANSI 87T – Differential protection
  • ANSI 87N – Earth-fault differential protection
  • ANSI 50/51 – Definite-time overcurrent-time protection as backup
  • ANSI 67 – Directional Overcurrent
  • ANSI 49 – Thermal overload protection
  • ANSI 46 – Load unbalance protection (negative-sequence protection)
  • ANSI 24 – Overexcitation protection

This test procedure shows how to test SIEMENS transformer relay with OMICRON Quick CMC module

Directional Overcurrent:

  • Enable the directional overcurrent in the digsi.
  • Enter the setting value in the Digsi:
  • Enter into the Setting Group A.
  • Select the DMT/IDMT Directional Phase/E Overcurrent.

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Non-Indian : $ 8 Click here to download

  • Then click Customize.
  • Enter the setting value in the Directional PH/E overcurrent –Setting group A.
  • After entering all the values, Click Ok.

Testing:
1) i) Set the fault phase current value higher than the secondary of the CT ratio. ii) Set the fault phase voltage value lower than the nominal value of PT.
2) In the signals select the fault appeared phase.
3) In the Quantity change the magnitude by Phase.

1) Click the Start button to start.
2) Keep the Phase angle at away from the operating zone. If ROC is 45o means then these are the operating region for the different phases.

3) Then press the Increase button as shown in the figure.
4) At the particular point the relay will get Trip. Note that value.
5) Again keep away from operating zone press the decrease button to find another operating point.
6) Note that Phase angle at which the relay gets tripped.
7) Compare those values with the Expected Operating region angle.
8) Then repeat this procedure for remaining two phases.

Download This Test Procedure (57 Pages, PDF format )

Indian : Rs 250 Click here to download

Non-Indian : $ 8 Click here to download

6 Replies to “SIEMENS Transformer Protection Relay Testing with Quick CMC”

  1. avatar

    this is best thing to happen for a relay testing engineer.. save time … please do more of this & excel sheet of relay calculations

    1. avatar

      Thanks for your comment and feedback, yes of course we will

  2. avatar

    HI,
    its great … can you do more like … generator protection, motor protection, transformer protection,bubar protection of siemens ,schneider, ABB and other manufacturers..if its good and it WORKS….every relay testing engineer…would be willing to pay a ransom…i bet

    THANK YOU FOR this one…

    1. avatar

      Hi, thanks Nitin for the suggestion. we consider this

  3. avatar

    Excuse me. I want to learn calculate differential relay characteristics.

    1. avatar

      Helpful Excel Spreadsheets for Protection Engineers maybe helpful for you : https://elec-engg.com/helpful-excel-spreadsheets-for-protection-engineers/