Re: Convertion of CIM CGMES format into a MATPOWER case struct

I know you want to convert in the direction CIM CGMES ==> MATPOWER, but just in case, the PowSyBl project has converters in the other direction: *

Re: DC/DC converter model

I don't think DC grids can be accommodated in MATPOWER (only DC links can, as far as I know). But I'll try to answer your question because we encountered this problem as well, a few years back. The context was steady-state power-flows in pure-DC microgrids. What we found at the time was that

Re: negative line parameters from psse_convert_xfmr

I remember I did check extensively the conversion of two-winding transformers a few years back; however, I did not check 3-winding ones. You can check those formulas in this article by Siemens: "Modeling of Three-Winding Voltage Regulating Transformers for Positive Sequence Load Flow Analysis in

Re: AC case network did not converge

Hello Asma, I thank you very much for your help, I understood the solution that you > proposed. I decreased the cos phi to finally have a max_lambda> 1, after > I saw the > value of Q which corresponds to the value of max lambda > 1 and I put the > Q for each turbine in negative like you did

Re: CPF with Modal Analysis

Hi Mariusz, I think the problem is that you have to provide a *solved* target case, because the Jacobian should be evaluated *at the solution*. Even for the base case, it wouldn't hurt to run a powerflow, since you can't always trust that the input file is a solved case. -- Jose L. Marin Grupo

Re: AC case network did not converge

Hello Asma, I gave your case a quick look and I found several problems with the file format (many extraneous lines in several places). Anyway, I was courious and I found that I could edit it by hand quickly because it's actually a rather simple and repetitive topology structure. I'm attaching

Re: AC case network did not converge

Hello Asma, Your description is not very clear, so let me ask you a couple of things first: - You seem to be saying that your generators should have P=8 MW. That's fine, but then you total load should be balanced according to that (is it?). Otherwise the imbalance, which has to be

Re: Branch model - switch FROM and TO bus?

Hello Elis, The ordering matters for the correct specification of the *tap ratio*. >From the manual (p. 21--22): "The transformer, whose tap ratio has magnitude $\tau$ and phase shift angle $\theta_{shift}$, is *located at the from end of the branch*, as shown in Figure 3-1". If, for whatever

Re: Power Flow in Matpower

Hello Mohammed, The problem is in the *branch joining buses 16 and 17* (line 191 in the file). This branch had zero R and zero X. Just edit the value of X to something reasonable (I used 0.001), and the case solves just fine, in 4 iterations. -- Jose L. Marin Grupo AIA 2018-03-21 3:51

Re: PF did not converge

Hi Mohammed, If you can share the mpc file you have constructed with all this data, maybe I could help. -- Jose L. Marin Grupo AIA 2017-12-14 18:55 GMT+01:00 Mohammed Alhajri : > Hello > > i tried to do a PF for a system whose data is attached, but PF did not > converge!

Re: Dear

Actually, you have to change the setpoint VG of the generator (or generators) attached to the slack bus: define_constants; mpc = loadcase('test'); % "test" is the name of your casefile mpc.gen(k, VG) = 1.023456 ; % k is the generator index of the generator(s) attached to your Slack bus --

Re: Regarding assigning initial values for load flow analysis in NR method in runpf() function

Hi Sayandev, As you know, iterative methods need an initial guess. But this is the user's *choice*: you can use a flat start as you mention, or any other information you may have (for instance, from previously solved cases that are similar to the one at hand---as it happens when solving N-1

Re: DC Power Flow

I don't mean to be disrespectful, but you should probably read this first: http://www.catb.org/esr/faqs/smart-questions.html Your question is way too broad and vague. -- Jose L. Marin Grupo AIA 2017-07-17 15:21 GMT+02:00 Saeed Ahmed : > I need to perform DC

Re: Qestions on case file data in Matpower

Check if they have it in one of these repositories, which are both part of ARPA-E's program "GRID DATA" (https://arpa-e.energy.gov/?q= arpa-e-programs/grid-data): 1. http://www.bettergrids.org/ Maintained by GridBright Inc and Utility Integration Solutions LLC (UISOL, a GE Company). 2.

Re: NREL-118 test case

Hi Zegal, You can check if they have it in one of these repositories, which are both part of ARPA-E's program "GRID DATA" (https://arpa-e.energy.gov/?q= arpa-e-programs/grid-data): 1. http://www.bettergrids.org/ Maintained by GridBright Inc and Utility Integration Solutions LLC (UISOL, a

Re: α and β of each transmission line

I think he may be referring to the real and imaginary parts of the line propagation constant gamma ( https://en.wikipedia.org/wiki/Propagation_constant). Note that this is a distributed parameter (i.e., per unit length of the line), while the parameters given in the *.m file are supposed to be

Re: Power flow VM VA, CPF end point

1. Yes, VM VA are used both for input and output. Note one subtle point, though: in runpf.m (Lines 177--183) the initial seed for the iteration is first set to the values [VM VA] provided as input, but for voltage-controlled buses (with active generators), the value of VM is replaced by the

Re: Wrong solution and Losses on the branches

Hi Mahraz, What is it exactly that makes you think the solution is wrong? If you want to perform an independent double-check on the solution, one way to do it consists simply in verifying current mismatches at every bus (which is the very expression of the power flow equations). When

Re: Load flow not convergent

By the looks of it, you may have bad data (or a badly formed) input case. You seem to have one or more NaNs somewhere in bus columns PD, QD, or BUS_TYPE. Note that, unless you have wacky errors of this kind, the technique mentioned in FAQ 5 (v) should always give you at least some solutions, at

Re: thanks & speeding up the Newton-Raphson power flow

any further comments you might have. > In particular, it appears that the vast majority of the speedup comes from > the AMD reordering and not from the Gilbert-Peierls algorithm. > > Ray > > > > > > Begin forwarded message: > > *From: *Jose Luis Marín

Re: RunPF vs GPU calculations

gt; > Thanks a lot > > On Thu, Dec 1, 2016 at 6:52 PM, Jose Luis Marín <mari...@aia.es> wrote: > >> Hello all, >> >> I've been meaning to report the following findings to Ray and the >> MATPOWER team for some time, but never got around doing it. Well, here it &

Re: RunPF vs GPU calculations

Hello all, I've been meaning to report the following findings to Ray and the MATPOWER team for some time, but never got around doing it. Well, here it is in summarized form: - There's a very cheap way to speedup the J \ F step (actually, the sparse LU decomposition) by factors of about

Re: Help on radial LV distribution network

If you want to do things properly, I guess you would have to do *all* of the following: - First, MATPOWER expects baseMVA to be in MW. If you want to use a p.u. system based around Volts and 1 kW (instead of the traditional kV and 100 MW), then you need baseMVA=0.001 at the beginning of

Re: Problem with runcpf

Just a guess: OPF observes limits QMIN and QMAX on generators, while a powerflow (with the standard option pf.enforce_q_lims=0) does not. Although not typical, it is certainly possible for a powerflow case to be infeasible when solving without generator MVAR limits, and solvable when enforcing

Re: restrictions regarding the ratio of PQ/PV buses in test cases

Hello Davor, This is actually a very interestng question from the point of view of the numerical stability of the equations. I asume that by "changing the bus type PQ --> PV" you mean the following: start by solving a given case, then take a particular PV bus and convert its generator injections

Re: How to use a Switch or Breaker in OPF?

MATPOWER, as most off-line planning tools, is "bus-branch" oriented, which means that it simply does not have the concept of switches and breakers. Each substation is typically represented with a single busbar at each nominal voltage level. However, you can simulate the action of breakers by

Re: Replacing constant power with constant impedance loads

I think that you have to invert the sign of QD. From http://www.pserc.cornell.edu//matpower/docs/ref/matpower6.0b1/idx_bus.html: columns 1-13 must be included in input matrix (in case file) 1 BUS_I bus number (positive integer) 2 BUS_TYPEbus type (1 = PQ, 2 = PV, 3 = ref, 4 =

Re: Performing N-1 contingency analysis

I'm attaching a structured script I wrote some time ago for carrying out N-1 contingency analysis. You may use it as a guide, but I'm sure you will need to make changes in order to adapt it to your specific needs (in particular, the metrics I compute were very specific of the analysis I was

Re: Convergence problems in a Microgrid

I guess the answer is "maybe", as it depends on the reactive power needs of both lines and loads. The best way to know is to start solving just regular powerflows before you attepmpt OPF. Make all solar panel generators run as PV-type (use VG=1 for all of them), and without enforcing Q limits

Re: Change 1 PQ to PV -> infeasible problem

t > doesn't converge. Maybe there is a problem with Newton's method?! > > Thanks for your help/explanations, nice regards, > Chris > > > 2016-05-06 7:33 GMT+02:00 Jose Luis Marín <mari...@aia.es>: > >> >> Sorry for the confusion, Ray: where I said, *"...solv

Re: A question about transformer modeling with uk, ur

Certainly, testing with a small system is the only way to find out what the internal model *really* is (since you can't inspect the code in this case). Anyway, I would add another suggestion: export from Netomac to PSS/E RAW format, and inspect the transformer records very carefully. Read the

Re: Change 1 PQ to PV -> infeasible problem

Sorry for the confusion, Ray: where I said, *"...solvable with the bus running as PV, but unfeasible when the bus is running as PQ"*, I meant to say: "*a valid powerflow solution* with the bus running as PV, but an *unstable* one when the bus is running as PQ" (it is one of the multiple