Re: Convergence problem in runpf for contingency

Hello Babulal, I believe that the problem is that MATPOWER does not automatically remove islands when running a powerflow. Each of the three contingencies you list happen to isolate a bus, therefore the network needs to be reduced prior to the call to runpf (Ray -- please correct me if I'm

Re: incorporating N-1 contingency

Hello Abhisek, As Ray said, you have to roll your own code, but it's pretty simple actually. I just had to prepare such a script recently, so I'm attaching it here in case it helps. Best regards, -- Jose L. Marin Gridquant España SL Grupo AIA On Sun, Nov 2, 2014 at 1:25 PM, abhisek mishra

Subtle bug in runpf when enforcing q_lims (strange behavior of MATLAB's union)

[I'm re-sending this to the list, I don't think it got through the first time] Hello Ray, I think I've stumbled upon a bug. It appears when enforcing generator q_lims, but only when there's exactly *one* generator violating the QMAX constraint AND *one* generator violating the QMIN constraint.

Re: IEEE 6-Bus System

As far as I know, there is no 6-bus test case from the IEEE. But there are actually two different 6-bus test cases out there: 1. The one used by Wood Wollenberg in their book (Section 6.15 of the 3rd Ed.). This one is case6ww.m in the MATPOWER distribution. 2. The one used by Garver,

Re: Calculation of a full Y-matrix

Jovan, I agree it's not fast and efficient, as it involves inverting the admittance matrix. However, I do not see why not Klein's impedance distance could be used in power networks. I mean, the fact that some (ok, most) injections are expressed as constant power does not invalidate the fact

Re: Calculation of a full Y-matrix

by my previous e-mail. Jovan On Tue, Feb 17, 2015 at 11:26 AM, Jose Luis Marin mari...@gridquant.com wrote: Jovan, I agree it's not fast and efficient, as it involves inverting the admittance matrix. However, I do not see why not Klein's impedance distance could be used in power networks

Re: IEEE 6-Bus System

Gridquant España SL Grupo AIA On Sat, Jan 3, 2015 at 5:34 AM, zahid khan zahid.haz...@gmail.com wrote: Dear Jose Luis Marin Thank you very much for your explanation.One thing is not clear to me that is regarding IEEE DATA set e.g IEEE 14 bus data or 1EEE 30 bus data etc.In state estimation

Re: RTS-96 Test System in matpower format

I found a copy here: http://www.mail-archive.com/matpower-l@cornell.edu/msg01301.html But I don't know if it really matches the actual RTS-96 data (see http://www.ee.washington.edu/research/pstca/rts/pg_tcarts.htm). If you get to analyze it in detail, could you please share the details here?

Re: power flow

Hello Lavanya, I guess you could achieve this by setting pf.nr.max_it to 1 (or pf.fd.max it or pf.gs.max it, depending on the powerflow method you use). See Table 4.2 in the Manual. -- Jose L. Marin Gridquant España SL Grupo AIA On Thu, Apr 9, 2015 at 9:28 AM, lavanya arubolu

Re: Regarding the Case39 data

The IEEE-300 model was originally created in the IEEE CDF format, which does not explicitly list loads as single devices, but just values of the P,Q drawn at the bus (similar to MATPOWER's mpc format, actually). As far as I know, nowadays the reference source is the archive at U. of Washington:

Re: increasing Reactive power load by a load factor

Hi Hiranya, Quick guess: I think you want to increase the initial values of PQ at bus 5 by increments of 20%, 40%, etc. If this is correct, then you need to change your loop more or less like this: define_constants; mpc = loadcase('case95'); y = mpc.bus(5,[PD QD]); for i = 1:10 mpc.bus(5,[PD

Re: PV curve using CPF

:16 PM, nilesh patel nk2...@rediffmail.com wrote: Sir, If i want to increase load in continuation power flow by step of 1 MW, What should be the step size of Lamda. My system base case load is 5000 MW. As CPF accuracy depends on step-size. Thanks. From: Jose Luis Marin mari

Re: convergence problem in runpf.

to have your steps up on the FAQ. Thanks, Shri From: Jose Luis Marin mari...@gridquant.com Reply-To: MATPOWER discussion forum matpowe...@list.cornell.edu Date: Wednesday, August 12, 2015 at 2:42 AM To: MATPOWER discussion forum matpowe...@list.cornell.edu Subject: Re: convergence problem

Re: convergence problem in runpf.

Mirish, I couldn't help notice that you're building this model from scratch (well, from a database) and you mentioned ***To make the problem simple I used all buses as PQ buses except one slack bus*. This actually makes it harder to converge, unless you have *very* accurate data on what the

Re: PV curve using CPF

Shruti is right, the value you obtain for lambda is valid for all the network, since voltage collapse is a global phenomenon (in other words, you'll see a nose point at the same value of lambda regardless of which bus you choose to plot). Remember that lambda represents a fraction along the

Re: psse2mpc conversion: bug in transformers with impedance code CZ=3?

(cz3) = R(cz3) .* Zb(cz3) ./ Zbs(fbus(cz3)); X(cz3) = X(cz3) .* Zb(cz3) ./ Zbs(fbus(cz3)); (and similarly for R,X of 3-winding transformers; note also that line 0107 has to stay for cz2 transformers). -- Jose L. Marin Gridquant España SL Grupo AIA On Thu, Oct 22, 2015 at 2:52 PM, Jose Luis

Re: Question about sparsity-based implementation in MATPower

he > thread launch and synchronization would most likely dominate. In addition, > one needs to be cognizant of issues such as thread affinity and first touch > when dealing with threads, which makes it harder for performance > optimization. > > Shri > > From: Jose Luis Marin <

Re: Nordic 32 model

You can obtain the Nordic 32 description in PSS/E v31 raw format from Bjorn Karlsson thesis here ( http://www.diva-portal.org/smash/get/diva2:658793/FULLTEXT01.pdf), and then use MATPOWER's conversion routine psse2mpc. Regards, -- Jose L. Marin Gridquant España SL Grupo AIA On Mon, Oct 26,

psse2mpc conversion: bug in transformers with impedance code CZ=3?

Hello Ray, I think I may have found a bug in *psse2mpc*, which concerns the calculation of R,X for transformers when these are specified with *"Impedance Code" CZ=3*. The PSS/E docs decribing the RAW format specify that, when CZ=3, the values in the file are: - R1-2 is the transformer load

About PV buses with negative P gens, and the implementation of dclines in powerflow (not OPF)

Hello Ray, I read section 7.5.3 of the manual about *DC transmission lines*, but I still have some questions in what regards simple *powerflow*: 1. As I understand it, the implementation will place dummy generators at each end. Are those buses then switched to PV type, taking the voltage

Re: Question about sparsity-based implementation in MATPower

I'd like to add that Matlab keeps incorporating the latest sparse direct solvers coming from Tim Davis and his group from TAMU / U. of Florida ( SuiteSparse ) into their new versions. I believe that if the Jacobian is symmetric, current versions

Re: About PV buses with negative P gens, and the implementation of dclines in powerflow (not OPF)

X. In this case, an extra constant > power factor constraint is added to the OPF problem. This does not affect > simple power flow. > 3. Yes. > >Ray > > On Oct 19, 2015, at 2:09 PM, Jose Luis Marin <mari...@gridquant.com> > wrote: > > Hello Ray, > > I read

Re: reg book reference

Hello, Try here: http://www.eng-tips.com/threadminder.cfm?pid=238 -- Jose L. Marin Gridquant España SL Grupo AIA On Mon, Dec 21, 2015 at 6:02 PM, ambi ka wrote: > sir > kindly tell me in which forum I have to ask for? > from > ambika > > > >

Re: Different results with MATPOWER and PSAT

I'll add my 2 cents. I don't know PSAT, but I can attest to the difficulty in reproducing exactly the same powerflow solution in two different software tools, in general. First you have to find out how many features are implemented and enabled/disabled in each tool; but more importantly, you have

Re: power flow question

warning > that the slack bus exceeded its capacity. Modifying the Jacobian was the > first thing that > came to my mind but I am not sure if it provides anything in addition of a > warning to user. > > Jovan > > > On Thu, Feb 18, 2016 at 3:25 AM, Jose Luis Marin <

Re: power flow question

But you did that, it would no longer be a powerflow calculation. There are good mathematical reasons why the standard powerflow calculation is formulated so that there should be at least one swing bus (where you specify both V and A, leaving P and Q "free"). If you specified V, A, and Pgen at

Re: Matpower 5.1 and constant impedance loads

Hello Jaroslaw, I may be completely off, as I do not know the RTDS system you're using, but I couldn't help noticing this sounds as if RTDS is using the "ZIP" (in your case just Z,P) load model components *only for transients*, not for static powerflow. But this is to be expected, because using

Re: question about losses

Hello Houssem, I don't know the reason why line Q-losses are reported that way in MATPOWER, but heuristically, if voltages are kept within reasonable bounds (say 0.9 to 1.10 in pu) then you can see that Q injections from line Bshunts will remain also bounded, as they are equal to Bs·V^2. By

Re: Change 1 PQ to PV -> infeasible problem

Sorry, one mistake in my example: the BUS_TYPE in the second case should obviously be 2 (PV), not 1. -- Jose L. Marin Grupo AIA On Thu, Apr 28, 2016 at 11:48 PM, Jose Luis Marin <mari...@gridquant.com> wrote: > > Looking at those records I think I may have misunderstood what yo

Re: Change 1 PQ to PV -> infeasible problem

Ray's suggestion is an excellent idea. I'd like to add the following. Suppose you start with "caseA", which solves ok. Now you make only one change to obtain "caseB": you switch one particular PQ bus to PV type, by carefully specifying its Vg as the voltage value you obtained in the solution of

Re: Change 1 PQ to PV -> infeasible problem

en if I increase the ref-Qmax to 1e20, Qmin to -1e20 - then the problem > repeats after converting the other 2 PV buses to PQ). > > (in a few hours I'll be without internet connection for 8 days so I wanna > apologize for not responding during the next days) > > Nice regards, >

Re: Change 1 PQ to PV -> infeasible problem

-600 Mvar > whereas the next most reactive power intensive gen has less than 5e2 > Mvar. I don't understand where the power comes from/goes to... > > @ Jose Luis Marin: > If I use the voltage from the PQ-calculation (e.g. 20.6668/20 p.u.) there > remains the same problem. Also