Thank you sir. I understand what you mean, so if I have to use the modified
ward equivalence in MATPOWER instead to eliminate all the load busses,
retaining only the 54 generator buses, would I not be faced with the problem
associated with the traditional Ward reduction like 'smearing' fractions of the
generator /load in the external buses across boundary buses? Also, is my code
right to obtain the reduction?
MATPOWER command used;
mpc = loadcase('case118');
ExBus =
[118,117,115,114,109,108,106,102,101,98,97,96,95,94,93,88,86,84,83,82,81,79,78,75,71,68,67,64,63,60,58,57,53,52,51,50,48,47,45,44,43,41,39,38,37,35,33,30,29,28,23,22,21,20,17,16,14,13,11,9,7,5,3,2]';
[mpcreduced,Link,BCIRCr]=MPReduction(mpc,ExBus,0)
[Y1] = ext2int(mpcreduced)
[Yreduced] = makeYbus(Y1)
Finally, what reduction method was adopted in MATPOWER for the equivalence, was
it Kron or any other. Thanks a lot.
From: [email protected]
[mailto:[email protected]] On Behalf Of Carlos E
Murillo-Sanchez
Sent: Monday, August 08, 2016 11:21 AM
To: MATPOWER discussion forum <[email protected]>
Subject: Re: Ybus-matrix
Hmm... that is an odd question. Looking at the Kron reduction myself, I find
that there are six off-diagonal elements with positive real parts, which would
imply six "lines" in this 54 bus "network" with negative resistance. I suppose
that you could actually synthesize values for pi models that would give you the
observed coefficients in the reduced matrix, but some of the parameters would
not be physically possible.
carlos.
Philip Adedotun Olaniyi wrote:
Thank you so much sir. My next question would be, is it possible to compute the
bus and branch tables from the 54-by-54 admittance matrix? Thank you
From:
[email protected]<mailto:[email protected]>
[mailto:[email protected]] On Behalf Of Carlos E
Murillo-Sanchez
Sent: Friday, August 05, 2016 11:10 AM
To: MATPOWER discussion forum
<[email protected]><mailto:[email protected]>;
[email protected]<mailto:[email protected]>
Subject: Re: Ybus-matrix
When you simplified away the PQ buses, you lost the ability to specify loads in
them. So, theoretically, you could perform a load flow in which you can only
have loads at the 54 generator buses. You cannot use runpf, though, as runpf
starts by building the Ybus matrix from the bus and branch tables; it does not
take Ybus as an input. You would have to call newtonpf.m directly with
suitable parameters.
carlos.
Philip Adedotun Olaniyi wrote:
Hi MATPOWER community,
I asked a question earlier and would like to modify it. I have a reduced
54-by-54 admittance matrix for case118. Can I use this as an input in MATPOWER
for my power flow analysis? How do I go about it?
I would appreciate your help. Thank you.
