Dear Igor, please see comments below.
Igor Verbruggen wrote:
Dear all,
I am attempting to use
MOST to formulate a DC security constrained OPF, with
preventive and corrective
naime ahmadi wrote:
Hello,
I want to calculate shunt capacitance (c) in the
attached figure.
In the branch data of MATPOWER we have b.
Is it correct to use this formulation to calculate c
c=b/(2*pi*f)
Slight correction:
Sf = V( mpc.branch(:, F_BUS) ) .* conj(Yf * V);
St = V( mpc.branch(:, T_BUS) ) .* conj(Yf * V);
carlos.
Ray Daniel Zimmerman wrote:
In matrix form, you can do the corresponding calculations
Ahmad Bariq Al Fahri wrote:
Thank you Carlos for the information.
As in Case 9, all bus voltage is specified to be 345 kV. If
the transformer defaults ratio is 1:1, does it mean that the
generator is connected in 345 kV
Ahmad Bariq Al Fahri wrote:
I would like to ask about case9.m (9 bus, 3 generators
case) system configuration. As I know that the parameters of
'TAP' (column 9) in the branch data are set to zero, does it
mean that the system does
naime ahmadi wrote:
Hello,
How can I change
the power
injection
to flow
measurement?
For
example, in the IEEE 14-bus system, bus 2 is connected to
buses 1,
Harun Hökelek wrote:
Dear all,
I’m trying to obtain bus impedance matrix of IEEE 33-Bus test system by
inversing admittance matrix.
However inv(makeYbus(case-data)) gives badly scaled or singular warning.
Is there any way to get the bus impedance matrix of this system?
Sincerely,
Harun
Dear
naime ahmadi wrote:
Dear Professor Ray,
I have a 3 bus system and want to calculate the DC Jacobian. I
attached the result that I want. My problem is that I do not know
which function in MATPOWER does exactly this calculation.
I also attached the 3 bus system in MATPOWER format.
Look at the
Müller, Tobias wrote:
Hello everyone,
I have problems when I
have a piecewise linear cost function on some generators
which increases slower after a break point as the power
Matthias:
You are specifying piece-wise linear costs with corner points at
(100, 1000) and (110,1000). That's a single flat linear segment,
which of course will have a marginal cost of zero. In general, if
these flexible generators are not against a
yangyang wrote:
Thank you Carlos, I have also found it; the tap should be the
ratio of per unit voltages instead of nominal voltages. But
after changing the tap to 1, the power flow shows that all buses
are 1 pu 0 degree, and it still
yangyang wrote:
Hi Carlos, I think there is a bus labeled 1 in the bus field,
next to the "mpc.bus" in the file, and it is a slack bus. If
there was not a slack bus, runpf() will report an error. So this
may not be the problem of my case...
yangyang wrote:
Dear all,
I am trying to construct the
power flow of IEEE 2nd benchmark for SSR study; and my
implementation is as attached. The capacity compensation is
55% and the other data can be found in the
Hi all;
Actually, what you need to do is to set equal linear costs for
all generators. If all linear cost coefficients are 1.0, for
example, then you get to minimize the sum of all generation, which
is a proxy for minimizing losses.
carlos.
Russ Patterson wrote:
Hi
- I am still trying to hand calculate the flow
into branch 2 from bus 1 to bus 2. I can’t get my results
to match MATPOWER.
I
get Q into the banks
Russ Patterson wrote:
Hi friends,
Per Table 4-2 in the manual, I
want to increase the number of iterations to solve my power
flow. So, I added a line to my .m file as you see below.
Russ Patterson wrote:
Hi
Carlos,
Thank
you. That makes sense. Based on that, I would expect to be
able to set the bus voltage, Vm, and it stick, but it
doesn’t. If I set
Russ Patterson wrote:
Hi
Uriel,
Is
there documentation (apologies if I missed it) that explain
how the power flow handles input data? For example, from
the case you
Rene Kruessmann wrote:
Hello everyone,
I have a question regarding how storages can get connected at different
positions within the grid. I want to add 2 storages, one at the top of the
grid and the other one at the bottom, that are connected with each other
to reduce the costs of redispatch.
Carlos Ferrandon Cervantes wrote:
Hello everyone:
I’ve been working quite a while with a UC problem
in MOST, using the IEEE RTS. I realised that when I compare the
mdo.UC.CommitSched results with mdo.results.ExpectedDispatch
Dear Yang:
If I understand correctly what you have in mind, then it seems to me
that you have two choices: 1) approximate the exponential in a limited
range with a higher order polynomial (which MATPOWER can easily handle),
or 2) write matlab code to implement user-defined cost functions
#FOO CEJUN, JOEL# wrote:
I am a student working on an OPF model for a 15 bus power
system.
I discovered an issue whereby the converged voltage magnitude
output values do not keep within the
Pfeifer, Lars Philipp wrote:
Hello everybody,
I have a question about the usage of the transformer in the branch matrix.
I have been reading the manual a few times and also took many looks in the
example cases.
But I still don’t really understand how I have to fill in the matrix for the
.
Please use it, break it, and tell us about any issues that you find.
Sincerely,
Carlos E. Murillo-Sanchez, Universidad Nacional de Colombia - Manizales
Sergio García Marín, Universidad Nacional de Colombia - Manizales
Wilson González Vanegas, Universidad Tecnológica de Pereira
To expand a little bit on Ray's
response: In power systems, we tend to have labels for very
specific kinds of problems;
one such label is "power flow" or "load flow". This refers to a
problem in which given some input parameters (values
of loads,
Reinhold Bertram wrote:
Dear all,
is it possible to speed up the repeated solving of a deterministic
multi-period dispatch problem with MOST when only the loadprofile changes?
At the moment SetupTime is about 2 seconds for each iteration. Is it
possible to skip/shorten this time?
Best
Actually, since the quadratic costs
that Mariusz wants are diagonal, it
is possible to use the normal polynomial cost mechanism in
mpc.gencost (including the cost on the reactive generations; see
the footnote in the manual at page 152).
Ismael K Abdulrahman wrote:
Dear Matpower community,
I have a system with one load bus faulted to ground (v=0). The system with
normal operation works fine. The system with the fault, however, cannot be
solved owing to low voltage problem. I tried to deal the faulted load bus as a
generator
Jubeyer Rahman wrote:
Hi,
I have several questions regarding the AC power flow in matpower.
a. I would like to know whether the AC Power Flow command ('runpf')
,when called, does it have any constraint to constrain the transformer
power rating violation which is related to the real and
amir ali Hosseini wrote:
Dear Sir,
i trying make a new network. 37 bus
but ! after runpf .i have warning!
can you help me ?
thanks a lot.
my warning is :
Warning: Matrix is singular to working precision.
> In newtonpf (line 89)
In runpf (line 204)
find attachment .
new network with 37 node.
wrote:
No, I don't
On Sun, Feb 10, 2019, 1:24 AM Carlos E
Murillo-Sanchez <ce.murillosanc...@gmail.com
wrote:
Do you
include reactive generation in the decision variab
2019 at 15:42,
Carlos E Murillo-Sanchez <ce.murillosanc...@gmail.com>
wrote:
Rather,
it seems that your optimization method should take into
account any constraint violation and fix the
Rather, it seems that your optimization
method should take into account any constraint violation and fix
the issue by itself. In some methods, such as GA, one way to do
this is by using penalty functions on constraint violations.
carlos.
naime ahmadi wrote:
Hi,
I have question about branch data in case 57 bus system in matpower.
When I look at diagram of IEEE 57 bus system, I can see it have some
crossing in the network between lines.
Are there any crossing in power system?
Thanks,
Naime
Hi Naime: Short answer is yes.
onsidering
the ramping up/down limits of the generation?
Kind regards,
Carlos Ferrandon
El mar., 4 dic. 2018 a las 16:30, Carlos E
Murillo-Sanchez (<ce.murillosanc...@gmail.com>)
Carlos: MOST models post-contingency
states explicitly, and these states influence the possible base
case states directly so that the base cases are secure in light of
the specific contingencies considered.
carlos.
Carlos Ferrandon Cervantes
Shiva Moshtagh wrote:
Hello
Can I use rectangular coordinates in matpower ? for example I know
that there are real and imaginary parts of power injections and power
flows as well as bus voltages, but for branch current there is not
rectangular coordinate. Suppose that I want to add
To clarify a little further on Ray's
advice:
An SVC can be approximated by a generator under voltage control
that can sink QMIN or source QMAX MVArs, but this would be
accurate for an SVC with a slope of infinity (i.e., constant
voltage). If you
The equations are generally available
in the OPF literature. For specific GAMS modeling, you may want
to look at
https://www.gams.com/latest/psoptlib_ml/libhtml/index.html
carlos.
Jane Cheung wrote:
Dear all,
nt. Thanks.
On Sat, Mar 31, 2018 at 12:41 PM,
Carlos E Murillo-Sanchez <ce.murillosanc...@gmail.com>
wrote:
Assuming
that the system data is in structure 'mpc', and that the
buses are numbered consecutively
.
Mostafa Mohammadpourfard wrote:
Thank
you, Carlos. May I ask you to write the code here? I am not a
power system student. Thanks
On Sat, Mar 31, 2018 at 9:41 AM, Carlos
E Murillo-Sanchez <ce.murillos
You have the bus voltages; now you just need to multiply the system's
nodal admittance matrix by the complex voltage vector to get the complex
currents vector. See the makeYbus function in MATTPOWER.
Carlos.
Arkan Arkan wrote:
Thank you, Ilias. But, unfortunately, there is not any direct
The Ybus matrix computed from the data
in your file has NaN's and Inf's because branch # 69 from bus 16
to bus 17 has zero series impedance. You must collapse buses 16
and 17 into a single bus before applying any algorithm to the
system because the electrical
Let's see, Mohammed: I tried the data
in MATPOWER format that you posted originally, and applied the
case_info(0) function to it, yielding the following results:
>> case_info(mpc)
Checking connectivity ... 3 connected groups, 1 isolated bus
Elapsed
In the actual optimization problem, everything is in per unit.
Therefore, you probably want to specify the right hand side of your
inequality as 70/mpc.baseMVA .
Carlos.
Teiji Ponishi wrote:
Dear all,
I am trying to add the following simple constraints by direct
specification.
0 <=
Matt: I have proof-of-concept code that implements line switching with
disjunctive constraints. Email me separately.
Carlos.
Matt Roveto wrote:
Hello,
I hope you are all well. I am trying to implement a transmission
switching DCOPF model to MATPOWER for use in a research project
according
bus
?
Thanks
On 4 Oct 2017, at 18:12, Carlos E
Murillo-Sanchez <ce.murillosanc...@gmail.com>
wrote:
Dear Chara
Dear Charalambos:
To begin with, you have a load of 894.31 MW (computed with
sum(mpc.bus(:,PD)) and a total generation capacity of 30
(computed with sum(mpc.gen(:, PMAX)) . Your slack generator has
PMAX specified as zero. And it seems to me that many
Stephen:
For hydro plants with reservoir, the way I have done this is by
assigning a daily (or weekly, depending on the length of the planning
horizon) amount of energy as the initial storage state, to be used
throughout the horizon optimally. As for the cost, it could even be
zero; the
Saeed: you need to add the sdp_pf
sub-folder to MATLAB's execution path.
carlos.
Saeed Ahmed wrote:
Hi
Community,
For
Making the he connection or bus incidence matrix i use
You can get an approximation to this on
the active power flow using the angular difference limits in
specified in the branch table. Columns ANGMAX and ANGMIN tell the
opf solver to implement
ANGMIN <= \theta_f - \theta_t <= ANGMAX
Carlos.
Oh, and by the way, do try IPOPT if you
still have not done so.
Carlos
Carlos E Murillo-Sanchez wrote:
Enrico:
I would certainly experiment with the values of the reactive
component of loads. In fact, an extreme
st regards,
Enrico
2017-02-25 22:01 GMT+01:00 Carlos E
Murillo-Sanchez <ce.murillosanc...@gmail.com>:
Perhaps
you can try to run an AC OPF with branches that are
represented only by the series re
Perhaps you can try to run an AC OPF with branches that are represented
only by the series reactance (no line charging capacitance nor
resistance); one of the AC solvers might be able to solve the resulting
problem.
Carlos.
Enrico Vaccariello wrote:
Dear all MATPOWER developers and users,
Brenda: That is exactly what the slack generator is expected to do in a
traditional load flow. I suggest that you look up any classic textbook
(Bergen, Wood & Wollenberg, etc.) and learn about the load flow problem
and its standard assumptions.
carlos.
BRENDA ROJAS DELGADO wrote:
Hi,
With the loading pattern in your
network, it is simply not possible to attain the voltage levels
that you want without using some sort of voltage compensation at
one or more locations. Even setting the voltage setpoint of the
source at 1.1 p.u., the resulting
Hi;
Looking at the diagram of the 118 bus system, it seems that the
branches in question are a combination of a transformer and a
line. Evidently, the pi model in the case data is an
approximation of this combined setup. But that is how the
...@list.cornell.edu
[mailto:bounce-120671035-76197...@list.cornell.edu]
On Behalf Of Carlos E Murillo-Sanchez
Sent: Friday, August 05, 2016 11:10 AM
To: MATPOWER discussion forum
<matpowe...@list.cornell.edu>;
The LMP are shadow prices (Lagrange multipliers) on the active nodal
balance. Even if there is no load at a bus, its balance equation must
still be fulfilled and it carries with it a multiplier in the lagrangian
function.
Mounika Vanjarapu wrote:
I have a doubt regarding the LMPs in an
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
, but we hope that it will
be useful for most people and most problems.
carlos.
Carlos E Murillo-Sanchez wrote:
Because modeling as a dispatchable
(up to Pmax) generator allows the optimization to curtail the
wind intake for security
From:
bounce-120538094-71172...@list.cornell.edu
[mailto:bounce-120538094-71172...@list.cornell.edu]
On Behalf Of Carlos E Murillo-Sanchez
Sent: Friday, June 03, 2016 11:29 AM
To: MATPOWER discussion
For each time period, there can be
several wind scenarios. The idea is to capture the variability of
wind, given a forecast, using those plausible wind realizations.
In each scenario, the Pmax value of the wind generator varies to
indicate the availability of
Dear Mounika:
We need to understand the nature of your question. It seems as if you
might be trying to force a two-stage decision problem onto the framework
of a single-stage one. Hence Ray's answer. Please ellucidate.
carlos.
Mounika Vanjarapu wrote:
sir
can we pose penalties for
the 32
bit version with the command
: matlab -maci
If you are running on windows, you might have the 32 bit version
somewhere in the Program Files-x86 folder.
Carlos.
Malcolm Barnacle wrote:
Dear Carlos E. Murillo-Sanchez,
I am trying to use the bpmpd solver for a dcopf problem. I have
Hi;
You have used the TAP column of the branch table to indicate two
transformers with a 55:1 ratio, and then you used the LV
impedances, I think, still in PU with a base voltage of 22KV; they
are pretty large. The TAP column should be used to specify
Dear Dominic:
The PF solver takes the generator voltage setpoint from the gen(:,
VG), thus changing the voltage values set by the OPF at generator
buses. Try
resultsOPF=runopf(mpc)
%calculate opf
1-28 20:34 GMT+01:00 Carlos E
Murillo-Sanchez ce.murillosanc...@gmail.com:
If there
is only one point of connection from the MV network to the
HV one, why can't you model this particular bus as a
reference bus with a generator that ca
Isabel:
Try creating a small band of acceptable voltage limits at the
generator bus
say VMIN = Vcenter - epsilon = V = Vcenter + epsilon =
VMAX, then start slowly
moving Vcenter from the initial optimization problem's solution
towards the
[ref pv, pq] = bustypes(bus, gen) ( or [ref pv, pq] =
bustypes(results.bus, results.gen) )
and then
results.bus(pq, VM)
carlos.
Kusi, Samuel A wrote:
Is there any way in MatPower to call out just the load voltages?
results.bus(:, VM) calls all buss voltages. Is there any code that can
It seems to me that you have an
instance of a data file which is aimed at detailed modeling of all
of the system's elements. This kind of data is useful for
graphical representation, but it poses a major problem: it
assigns different bus numbers to elements that
Dear Jiashen:
The model used in Matpower is the standard pi one-line equivalent of a
three phase transmission line, with quantities in per-unit. This is
constructed from a base voltage equal to sqrt(3) times the phase voltage
and a base power equal to three times the per-phase power. With
One possible way, using system replication to build an augmented system
with coupling constraints among the different islands, is what we
originally employed a few years ago for this:
http://www.sciencedirect.com/science/article/pii/S0167923613001152
linhomeperson wrote:
Dear MATPOWER users,
Mr. Acker:
The mathematical problem that is solved behind the scenes is simply
singular in light of such modeling detail. Any robust solver would
actually look for such occurences in the data and collapse the busbars
into a single one, and then, as a post-solution-processing strategy,
split
As well as adding coordination costs in
separation and coordination optimization schemes :-) .
Ray Zimmerman wrote:
The basekV column of the bus matrix has no effect on the
solution.
I am not aware of any real cost
Unfortunately, this problem is of an
intrinsic nature. If it is an OPF that you are running, you might
try using additional linear constraints to equate the two bus bars
magnitudes and angles, and hope that the underlying linear algebra
algorithms will deal with
Ahmad:
If baseMVA is 100, then Bs in pu should be 0.19 .
carlos.
ahmad rezaee wrote:
Dear
Dr Zimmerman and all friends
I
have written one load flow code with Gauss-Sidel and one with Newton-Raphson.
Both of them lead to the same results. For validating my codes I compared the
results
Santiago:
You can use a piecewise linear cost model with two segments, with vertex
points
at (-Qnegmax, Qnegprice*Qnegmax), (0,0), (Qposmax, Qposprice*Qposmax) .
Santiago Torres wrote:
Dear Ray and Matpower friends
I want to use the reactive power cost of AC optimal power flow. I
You can specify bus shunt conductances and capacitive susceptances in
the GS and BS columns of the bus matrix as MW and Mvars at nominal
voltage. And yes, the assumption that loads are modeled as PQ quantities
is standard in the load flow problem. Using a different model for loads
is a
Dear Bela:
Running MINOPF on the system, it seems that both active and reactive
balances are hard to fulfill in bus 706.
Carlos.
Bela Genge wrote:
Dear all,
I am having some problems running an AC power flow with the attached
case system. This is an approximate EU Power Grid model that
Richard:
One easy way to minimize losses using the opf solver is to assign to all
generators the same linear fuel cost. If all sources have the same
cost, then the optimizer will try to minimize losses. However, you have
to provide sensible VMIN, VMAX limits for all buses in the bus table,
Hi;
Unfortunately, the original data does not include those
parameters.
A while ago, based on information about base transmission line
voltage, standard conductor sizes, and information about whether
certain lines were single or double
Iman: two methods are compared in this paper. The 2-point estimate
tries to capture moments of the distribution using just two
_deterministic_ OPFs. The cumulant method assumes linear propagation
(i.e., based on a sensitivity analysis of the KKT conditions) of the
pdfs of the quantities
I think that this is actually a good review of the issues involved in
attempting a true probabilistic power flow:
http://ieeexplore.ieee.org/xpl/login.jsp?tp=arnumber=4523658url=http%3A%2F%2Fieeexplore.ieee.org%2Fiel5%2F4511470%2F4523365%2F04523658.pdf%3Farnumber%3D4523658
iman wrote:
Dear
Hi;
There are diagrams for the ieee 30 bus system and the 118 bus system
around, may also for others.
I will send you these two in a separate mail.
carlos.
Shri wrote:
On Aug 20, 2012, at 11:11 AM, Carlos E Murillo-Sanchez
ce.murillosanc...@gmail.com wrote:
Power networks are usually
Hi;
I am not sure that I completely follow your second question. With
regards to the first one, we really have just the ones that are
distributed with MATPOWER, plus some others that we use in research and
which may contain propietary data.
Your second question... if the solvers find a
Let me see if I get this rightt:
1) You define real power dispatches of non-slack generators in a test
case, perhaps also change the amount of load, and then
2) you run a power flow, ostensibly with runpf. But then,
3) you find that the dispatch values that you had defined in step (1)
for
my question is what is MATPOWER doing for solving the DC power flow
that causes this.
It would be of great help to me if you answer this.
All the best,
Hanie
On Tue, Aug 21, 2012 at 2:46 PM, Carlos E Murillo-Sanchez
ce.murillosanc...@gmail.com mailto:ce.murillosanc...@gmail.com wrote:
Let
, Carlos E Murillo-Sanchez wrote:
I can envision that this method of randomly connecting two systems might easily
create unsolvable systems, with wild angular differences even if solvable.
That is not how transmission networks are designed.
Thanks for your comments Carlos. Any tips on how to go
So, if the reactive dispatch of your generators is constrained to be
within a 0.95 power factor, then you can use MATPOWER's trapezoidal
modeling of the (P,Q) feasible region. as opposed to simple bound
constraints on P and Q
for a generator. In your case, if Pmin reaches down to 0, then you
Hi Rui;
Unfortunately MATPOWER uses one-line equivalent flows, so it cannot do
unbalanced three-phase analysis.
carlos.
Rui Ferreira wrote:
Dear Sirs,
I built a small network to represent a branch of low voltage grid, I
have a transformer 400 kVA 15kV/400V and downstream I have the LV
Um, an unfortunate crisscross with acronyms... by PV generators do you
mean power-voltage as in classical power flow problem parlance or do you
rather mean photo voltaic?
Richard Ngonga wrote:
Hi there,
I am working on a thesis on reactive power control on a distributed
network with
I can envision that this method of randomly connecting two systems might
easily create unsolvable systems, with wild angular differences even if
solvable. That is not how transmission networks are designed.
Shri wrote:
Hi,
I am trying to create a bigger test case by duplicating a
Iman:
The power flow is a deterministic problem, because you cannot have PF
variables obey Kirchhoff's laws in a valid probabilistic manner.
However, you can have probability-weighted deterministic power flow
scenarios representing some distribution, and depending on what kind of
things you
If the angles change from the value in the data tables after you run
runpf(), then it just means that the initial data is not a steady state
solution to the AC power flow, and therefore such data is meaningless.
There is no before this shift has happened.
carlos.
Hanie Sedghi wrote:
Dear
There is a rather flexible utility in matpower for scaling loads. Type
help scale_load
at the matlab prompt for help on how to use it. Otherwise, if you just
want to modify inflexible demand,
you could do something like
mpc = loadcase('case118');
define_constants;
Nominal_PD = mpc.bus(:,
Oops, that fourth line should be
Nominal_QD = mpc.bus(:, QD);
Carlos E Murillo-Sanchez wrote:
There is a rather flexible utility in matpower for scaling loads. Type
help scale_load
at the matlab prompt for help on how to use it. Otherwise, if you
just want to modify inflexible demand
André:
The ratio that is to be entered is a tap ratio for transformers that
have variable tap ratio capability, not a turns ratio; Tap ratios are
usually close to unity, say within [0.95, 1.05] . Turn ratios are done
away with in per unit modeling. And phase shifting transformers (a
Hello;
An optimal power flow, when confronted with an incremental load change,
dictates a distributed
slack-taking rule that maintains optimality conditions.
"The proportion is fixed for an incremental load change in any bus" -
yes, if the costs are linear.
If the costs are adequately
Are you running 32 or 64 bit Matlab? The mex file is 32 bit and
can only run under 32 bit Matlab.
Berk Kapicioglu wrote:
Dear colleagues,
I would like to use bpmpd. I found it while searching for a
state-of-the-art QP solver that is super fast and can deal with sparse
matrices when
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