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Monitor branch current in dynamic study

asked Nov 29 '18

sy_fung gravatar image

updated Nov 29 '18

Hi, How can I monitor branch current as an output channel in dynamic simulation?

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answered Nov 30 '18

perolofl gravatar image

Unfortunately, PSSE doesn't have any channel for branch current. I see at least three alternatives for you.

  1. Calculate from line MVA and bus voltage. Add channels with line MVA flow and bus voltage magnitude. Use a function in plotbook to calcuate I = MVA / Vpu / base voltage / 1.73205 to get the current in kA.

  2. Use a line relay model, e.g. TIOCR1, with dummy parameters and assign the model VAR containing the line current into a channel. The line current will be in pu.

  3. Write a user written model that calculates the line current and assigns it to a VAR. Add a channel for the model VAR. This is how I solved it myself!

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Thanks for the reply. I am trying to simulate a frequency disturbance event and compare the simulation with my V and I data. The formula in #1 should only valid in steady state and may not give accurate result when frequency changes. I am wondering if you have any examples to show how #2 works?

sy_fung gravatar imagesy_fung (Nov 30 '18)

And how I can assign model VAR into a channel? Do you know any documentation which talks about how P, Q are calculated in PSSE dynamic simulation in the scenario when frequency changes?

sy_fung gravatar imagesy_fung (Nov 30 '18)

Why shouldn’t the formula give accurate result when frequency changes? I have never used alt. 2 since I am using alt. 3.

perolofl gravatar imageperolofl (Nov 30 '18)

Add a VAR to a channel with the VAR/STATE channel selection tool. Menu: Dynamics - Define simulation output - Misc quantity. It is important to select "Network frequency dependence" option in "Dynamic simulation options".

perolofl gravatar imageperolofl (Nov 30 '18)

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Asked: Nov 29 '18

Seen: 1,666 times

Last updated: Nov 30 '18