Dear Mr. David Vowles,
I think maybe you pay attention to the transient process of the short circuit
current. But I just want to find the value of its periodic part when t=0 if the
failure point is far away with the generators. Of course, it's an approximate
result. But if I don't care about the precision so much, I think it's a useful
method, which so called as 'the practical calculation for the 3-phase SC' in
many books. Then I can get any short circuit current from the matrix of
impedances or admittances.
As to V(0), it can be computed after the calculation of the power flow for one
time.
Yours sincerely,
Wu Jun
Unit: State Key Lab. of Power Systems,
Dep. of Electrical Engineering,
Tsinghua University, P.R. China.
Email: [email protected]
2007-04-18
发件人： David Vowles
发送时间： 2007-04-18 17:02:03
收件人： MATPOWER discussion forum
抄送：
主题： Re: About the short circuit current (I think Matpower can calculate it)
Dear Wu Jun,
I do not believe that the approach you propose will work because the
power-flow equations (normally) do not include the machine reactance. As
you know, when calculating the short-circuit impedance at a network
node, synchronous machines should be represented by a constant-voltage
behind an appropriate impedance. The appropriate impedance might
typically be the sub-transient reactance or transient reactance of the
machine, depending on the time-frame of interest. In the loadflow
computation, (typically) the generator terminal voltage is constant,
which represents the longer-term response of the machine due to the
action of the automatic voltage regulator (AVR).
Hope this helps,
David.
Wu Jun wrote:
> Ara and others,
>
> I think the short circuit currents (3-phase SC) can be easily calculated by
> the practical formula shown as below, isn’t it?
> Id=V(0)/Zdd
> where Id is the short circuit current (3-phase SC), V(0) is the initial
> voltage at the failure point and Zdd is the self-reactance of the failure
> point.
> So I think Matpower can also calculate it because all elements in the right
> side of the formula can be achieved in the process of calculating the power
> flow. But I am not familiar with the inner structure of Matpower.
> I am wondering how to get the Zdd from it?
>
> --------------
> Yours sincerely,
> Wu Jun
> Unit: State Key Lab. of Power Systems,
> Dep. of Electrical Engineering,
> Tsinghua University, P.R. China.
> Email: [email protected]
> 2007-04-18
>
>
>
> 发件人： Panosyan, Ara
> 发送时间： 2007-04-13 20:21:58
> 收件人： [email protected]
> 抄送：
> 主题： [?? Probable Spam] WG: Re: About the short circuit current
>
>
> Wu,
>
> as I wrote in my first email, I am not sure what each tool can, since I
> haven't used any of them, but I thought maybe you would be interested in
> knowing about the available Matlab Tools for PS-Analysis.
>
> I am not sure what kind of analysis do you mean? Do you want to calculate
> only the short circuit currents (3-phase SC)? Or the dynamic fault analysis?
> I guess if it’s the 2nd one, then you should be able to use many tools. Short
> circuit current calculation according to standard procedure (i.e. IEC 909 or
> ANSI http://ieeexplore.ieee.org/iel1/28/5799/00222435.pdf?arnumber=222435) is
> probably a bit trickier to program, because of its unsystematic nature. Maybe
> that’s why most tools still don't have it.
>
> Regards
>
> Ara
>
>
> ------------------------------------
> Dipl.-Ing. Ara Panosyan
> University of Hannover
> Institute of Electric Power Systems
> [email protected]
> ------------------------------------
>
>
> -----Ursprüngliche Nachricht-----
> Von: [email protected]
> [mailto:[email protected]] Im Auftrag von ??
> Gesendet: Freitag, 13. April 2007 10:44
> An: MATPOWER discussion forum
> Betreff: Re: [?? Probable Spam] Re: About the short circuit current
>
> Ara,
>
> Thanks for your attention and suggestion.
> I've read the paper and gotten more information about the PSAT from the
> author's homepage. But unfortunately, the author said below words in one
> presentation: The fault analysis and some other tools are still not available
> as Matlab packages or toolboxes. So I have to go on looking for other tools.
>
> --------------
> Yours sincerely,
> Wu Jun
> Unit: State Key Lab. of Power Systems,
> Dep. of Electrical Engineering,
> Tsinghua University, P.R. China.
> Email: [email protected]
> 2007-04-13
>
>
>
> 发件人： Panosyan, Ara
> 发送时间： 2007-04-12 21:09:08
> 收件人： MATPOWER discussion forum
> 抄送：
> 主题： [?? Probable Spam] Re: About the short circuit current
>
> Wu,
>
> check this paper for some of the available Matlab based PS-Tools.
> But it doesn't look like any of them has the IEC-standard short-circuit
> calculation (if that is what you are looking for?).
> I'm not sure thought, since I haven't used any of them.
>
> http://www.power.uwaterloo.ca/~claudio/courses/ece664/project/PSATpaper.pdf
>
> Ara
>
> ------------------------------------
> Dipl.-Ing. Ara Panosyan
> University of Hannover
> Institute of Electric Power Systems
> [email protected]
> ------------------------------------
>
>
> -----Urspr�ngliche Nachricht-----
> Von: [email protected]
> [mailto:[email protected]] Im Auftrag von ??
> Gesendet: Donnerstag, 12. April 2007 14:31
> An: matpower-l
> Betreff: About the short circuit current
>
> Hi all,
>
> Can the Matpower calculate the short circuit currents?
> If it can not, which one can? Please introduce one toolbox in MATLAB for me.
> Thanks!
>
>
> --------------
> Yours sincerely,
> Wu Jun
> 2007-04-12
>
--
David Vowles,
Research Engineer,
School of Electrical and Electronic Engineering,
The University of Adelaide,
Australia, 5005.
Phone: +61 8 8303 5416
Fax: +61 8 8303 4360
