Hi Dr. Zimmerman,
Just to let you know that currently I am analyzing branch flows in a
modified IEEE 118 benchmark problem. I have observed that there exists
cases as given in red below in where the *To* and *From *bus *P value* is
(+) which means that it is giving to each other, hence the losses is the
sum of both the (+) values, hence does this mean that the flow is 0 on this
branch? and is there possibility for both to and from end to be receiving
from each other too (both P values (-)). And if there is than what is the
branch flow?
Branch Data
|
========================================================================
Brnch From To From Bus Injection To Bus Injection Loss (I^2 *
Z)
# Bus Bus P (MW) Q (MVAr) P (MW) Q (MVAr) P (MW) Q
(MVAr)
77 54 55 -4.99 -72.73 5.89 74.39
0.895 3.74
78 54 56 7.75 -633.11 3.53 671.51
11.276 39.
Thank you for your valuable time.
Sincerely,
Sashi
On Thu, Oct 3, 2013 at 3:39 AM, Ray Zimmerman <[email protected]> wrote:
> The real power loss in branch *k* can be computed as ...
>
> Ploss = results.branch(k, PF) + results.branch(k, PT)
>
> Also, I just noticed my previous response had an error in it. The voltage
> angles used to compute Vf and Vt need to be multiplied by pi/180 to
> convert from degrees to radians.
>
> --
> Ray Zimmerman
> Senior Research Associate
> B30 Warren Hall, Cornell University, Ithaca, NY 14853
> phone: (607) 255-9645
>
>
>
>
>
> On Oct 2, 2013, at 2:18 AM, Muhammad Buhari <
> [email protected]> wrote:
>
> Hi,
>
> Pls can you help me with an advice on the best method to compute the
> branch losses using matpower
>
> Thanks for your continued assisstance.
>
> Regards
>
> Muhammad Buhari
>
> PhD student
>
> Electrical Energy and Power Systems Research group,
>
> University of Manchester, UK
> ------------------------------
> *From:* [email protected] [
> [email protected]] on behalf of Ray Zimmerman [
> [email protected]]
> *Sent:* 30 September 2013 8:22 PM
> *To:* MATPOWER discussion forum
> *Subject:* Re: Branch Currents in matpower 4.1
>
> For branch *k*, connecting bus *f* to bus *t*, you can calculate them
> directly from the bus voltages and branch powers.
>
> Sf = results.branch(k, PF) + 1j * results.branch(k, QF);
> St = results.branch(k, PT) + 1j * results.branch(k, QT);
> Vf = results.bus(f, VM) * exp(1j * results.bus(f, VA));
> Vt = results.bus(t, VM) * exp(1j * results.bus(t, VA));
> If = conj( Sf / Vf ); %% complex current injected into branch k at bus f
> It = conj( St / Vt ); %% complex current injected into branch k at bus t
>
>
> --
> Ray Zimmerman
> Senior Research Associate
> B30 Warren Hall, Cornell University, Ithaca, NY 14853
> phone: (607) 255-9645
>
>
> On Sep 28, 2013, at 11:24 AM, Jiashen Teh <[email protected]>
> wrote:
>
> Hi
>
> I would like to know the method to calculate correctly the branch currents
> from the matpower results.
>
> Regards
>
>
> Yours sincerely,
>
> Jiashen Teh
> PhD Student
> Electrical Energy & Power Systems Group, School of Electrical & Electronic
> Engineering
> Ferranti Building (B18), The University of Manchester, M13 9PL, United
> Kingdom
> Tel: +44 (0) 161 306 2263; Mobile: +44 (0) 792 322 4864
> ------------------------------
> *From:* Muhammad Buhari
> *Sent:* 28 September 2013 16:19
> *To:* Jiashen Teh
> *Subject:* Branch Currents in matpower 4.1
>
> Hi,
>
> Please can you help me with the method to calculate correctly the branch
> currents from the matpower results.
>
> Regards
>
> Muhammad Buhari
>
> PhD student
>
> Electrical Energy and Power Systems Research group,
>
> University of Manchester, UK
>
>
>
>
>
