Hi all,
I am working on capacitor placement for power factor (PF) improvement.
The capacitor is modeled as BS in the bus matrix. While the PF is computer
as ratio of sum of Pgen to Sum of Sgen.
My results shows improve PF, but the losses are increasing. My expectations
is that the losses will
>From Section 6.4.2 Dispatchable Loads in the Manual …
… the model used in MATPOWER assumes that dispatchable loads maintain a
constant power factor. When formulating the AC OPF problem, MATPOWER will
automatically generate an additional equality constraint to enforce a constant
power fac
I don’t know of any straightforward way to do this in MATPOWER. You’ll need to
add user-defined linear constraint to force the relationship between real and
reactive power to keep the power factor constant.
Turns out this question has already been addressed on the MATPOWER forum.
https
Hi, everyone.
by use dispatchable load, we can have load shedding in OPF.
How can have load shedding by keeping power factor of loads?
Thank you so much for consideration and help.
3rd
generator.
Ray
> On Jul 21, 2016, at 10:07 AM, Ibtihal Abdelmotteleb
> wrote:
>
> Dear Prof. Ray,
> I have a question regarding fixing the power factor of the generators.
> Within the mail archive, I found a previous reply from you to a similar
> question:
>
Dear Prof. Ray,
I have a question regarding fixing the power factor of the generators.
Within the mail archive, I found a previous reply from you to a similar
question:
define_constants;
mpc = loadcase('case9');
nb = size(mpc.bus, 1);
ng = size(mpc.gen, 1);
pf = 0.95;
QPratio = sqrt
sorry about that. I really apologize for the way of writing.
> So sorry about that.
>
> Would you mind letting me know how I can modify the code in order to have
> variable power factor? I was not able to apply your comments. I'll be very
> grateful if you can help me please.
>
sorry about that. I really apologize for the way of writing.
> So sorry about that.
>
> Would you mind letting me know how I can modify the code in order to have
> variable power factor? I was not able to apply your comments. I'll be very
> grateful if you can help me please.
>
n order to have
> variable power factor? I was not able to apply your comments. I'll be very
> grateful if you can help me please.
>
> Once again, I do apologize.
>
> Best regards,
>
> Carlos
>
> On Fri, Sep 25, 2015 at 6:34 PM, Ray Zimmerman <m
Dear Prof. Zimmerman,
I am really sorry about that. I really apologize for the way of writing. So
sorry about that.
Would you mind letting me know how I can modify the code in order to have
variable power factor? I was not able to apply your comments. I'll be very
grateful if you can he
Dear Prof. Zimmerman,
I am really sorry about that. I really apologize for the way of writing. So
sorry about that.
Would you mind letting me know how I can modify the code in order to have
variable power factor? I was not able to apply your comments. I'll be very
grateful if you can he
= mpc.A(2:10, :);
>
>>>> mpc.l = zeros(ng-15, 1);
>>>> mpc.u = mpc.l;
>
>>
>>
>> Best regards
>>
>> C
>
>
> On Tue, Sep 22, 2015 at 2:25 PM, Ray Zimmerman <mailto:r...@cornell.edu>> wrote:
> That wouldn’t be correct a
-ones(ng,1)], ng, 2*nb+2*ng);*
>> *mpc.A = mpc.A(2:10, :);*
>>
>> *mpc.l = zeros(ng-15, 1);*
>> *mpc.u = mpc.l;*
>>
>>
Best regards
C
On Tue, Sep 22, 2015 at 2:25 PM, Ray Zimmerman wrote:
> That wouldn’t be correct anyway. The power factor is not the same as t
That wouldn’t be correct anyway. The power factor is not the same as the Q/P
ratio. And you will need two separate sets of constraints, one for the upper
bound on the power factor and the other for the lower bound on the power factor.
Ray
> On Sep 22, 2015, at 2:56 AM, Carlos Ma
t you are having
> trouble understanding?
>
> It is setting up a constraint *l* <= *A* * *x* <= *u*, where *x* = [*Va*;
> *Vm*; *Pg*; *Qg*], so you need to define the *A*, *l* and *u* to restrict
> the *Qg*/*Pg* ratio in a way the enforces the power factor range you
> desire. You
here x = [Va; Vm; Pg; Qg], so
you need to define the A, l and u to restrict the Qg/Pg ratio in a way the
enforces the power factor range you desire. You have an example of how to
enforce the Qg/Pg ratio to a specific value that corresponds to a given power
factor. Once you understand that, it sho
nderstanding?
>
>Ray
>
>
> On Sep 1, 2015, at 11:58 AM, Carlos Marta Gonzalez Almeida <
> cgonzalezalme...@gmail.com> wrote:
>
> Dear Dr. Zimmerman,
>
> According to your previous posts on the following equation which makes the
> power factor constant. No
load p.f. = cos(atan(Q/P)).
By changing the P and Q values, you should be able to set the desired
power factor.
Shri
-Original Message-
From: Hiranya Seneviratne
Reply-To: MATPOWER discussion forum
Date: Tuesday, June 2, 2015 at 10:43 AM
To: MATPOWER discussion forum
Subject: Re
Dear Shri,
Thanks a lot. Is it possible to change the power factor as well?
I thought only the magnitudes of p and q can be changed in that manner?
Thank you
Sent from my iPhone
> On 2 Jun 2015, at 16:31, "Abhyankar, Shrirang G." wrote:
>
> Before running the power flow,
Before running the power flow, you can change the load P and Q values in
the bus data.
Shri
-Original Message-
From: Hiranya Seneviratne
Reply-To: MATPOWER discussion forum
Date: Tuesday, June 2, 2015 at 6:17 AM
To: MATPOWER discussion forum
Subject: Power factor
>Dear Ray,
>
Dear Ray,
Is it possible to change the load power factor in matlab when running a power
flow simulation?
Thank you
Hiranya
Just a friendly reminder to everyone, please do a quick search of the mailing
list archives before posting your questions. There is a lot of good stuff
hidden there.
The following post contains an example of setting a constant power factor
constraint. Turning it into a set of inequality
How can I implement a power factor constraint in the OPF solution? What if
all generators will have to operate within a certain pf range? let's say
all generators must operate within 0.85 lag to 0.95 lead. How do I
implement this?
ve read decide optimal location, optimal size and "optimal
> DG power factor", but in manual appendix B how to change power factor of
> generator is not written.
>
> I want to optimize location , size and power factor.
> Can matpower treat power factor of generator?
>
load power
factor held constant. This optimization would give you the optimal size for the
DG but _not_ the optimal power factor.
For obtaining optimal power factor of the DG, one way is to include
minimization of the reactive power of the DG in the OPF objective function. You
can do this by
PE)=2, mpc.gen(,PG)=100...".
Journal I have read decide optimal location, optimal size and "optimal
DG power factor", but in manual appendix B how to change power factor of
generator is not written.
I want to optimize location , size and power factor.
Can matpower treat power
If you mean that you would like to constrain the power factor of a distributed
generator to remain constant as it gets redispatched by the OPF, then, yes, it
is possible. You will have to add a user-defined linear equality constraint for
each distributed generator. This is already done for
Hello,
I have a question about power factor.
I have read many journal about distributed generator insertion.
Journal I have read treat power factor of distributed generator.
I want to treat power factor of distributed generator, but how to treat
power factor of distributed generator is not
This is the kind of thing that you should be able to derive very easily by
looking up the definition of power factor and how it relates to the ratio of Q
and P. I think it's just a sign change.
--
Ray Zimmerman
Senior Research Associate
419A Warren Hall, Cornell University, Ithaca, NY
or you, I think I got the
> inequalities correct.
> --
> Ray Zimmerman
> Senior Research Associate
> 419A Warren Hall, Cornell University, Ithaca, NY 14853
> phone: (607) 255-9645
>
>
>
>
> On Feb 6, 2012, at 9:13 AM, Roberto Carvalini wrote:
>
>> D
9645
>
>
>
>
> On Feb 6, 2012, at 9:13 AM, Roberto Carvalini wrote:
>
> Dear Ray,
>
> According to your reply to one of the posts as you specified a predefined
> PF as follow. Now, I want to have only a range of Power Factor, for
> example, between 0.9 and 0.8. What change
> Dear Ray,
>
> According to your reply to one of the posts as you specified a predefined PF
> as follow. Now, I want to have only a range of Power Factor, for example,
> between 0.9 and 0.8. What changes I have to do in the following program in
> order to have va
I think you need to take some time to understand the examples I already gave.
If you understand them, the answer to your question should be obvious. Simply
eliminate the row of A corresponding to the generator whose power factor you
want to free up.
--
Ray Zimmerman
Senior Research Associate
one with a free power factor and large enough
> reactive power range to balance the reactive power in the system.
>
> --
> Ray Zimmerman
> Senior Research Associate
> 211 Warren Hall, Cornell University, Ithaca, NY 14853
> phone: (607) 255-9645
>
>
>
> On Mar 14,
You have to leave at least one with a free power factor and large enough
reactive power range to balance the reactive power in the system.
--
Ray Zimmerman
Senior Research Associate
211 Warren Hall, Cornell University, Ithaca, NY 14853
phone: (607) 255-9645
On Mar 14, 2011, at 11:53 AM
tage
>>> angles (1st nb columns) and magnitudes (next nb columns), so it's in column
>>> 2*nb+1. For Qg(1) it's the first column after the Pg columns, so 2*nb (for
>>> the voltage angles and magnitudes) plus ng columns for Pg.
>>>
>>> Yes, if you
mns), so it's in column 2*nb+1. For
>> Qg(1) it's the first column after the Pg columns, so 2*nb (for the voltage
>> angles and magnitudes) plus ng columns for Pg.
>>
>> Yes, if you wanted to do this for all generators, you need to include a row
>> in A
;s the first column after the Pg columns, so 2*nb (for
>> the voltage angles and magnitudes) plus ng columns for Pg.
>>
>> Yes, if you wanted to do this for all generators, you need to include a
>> row in *A* for each. Be careful though, this will likely over-constrain
>> th
he Pg columns, so 2*nb (for the voltage
> angles and magnitudes) plus ng columns for Pg.
>
> Yes, if you wanted to do this for all generators, you need to include a row
> in A for each. Be careful though, this will likely over-constrain the problem
> and make it infeasible. If
-constrain the
> problem and make it infeasible. If all generators have a fixed power factor,
> then balancing the real power output to match the load will mean a specific
> reactive power output as well, which will not necessarily match the reactive
> power load.
>
> --
&g
em and
make it infeasible. If all generators have a fixed power factor, then balancing
the real power output to match the load will mean a specific reactive power
output as well, which will not necessarily match the reactive power load.
--
Ray Zimmerman
Senior Research Associate
211 Warren Hall, Cor
Dear Prof. Zimmerman
Thank you very much for your help.
I don't know what changes should be applied to the following code to have
PF=0.95 for other generators. I cannot obtain the same power factor(0.95, I
obtained 0.99 or other values). If it is possible please help me.
Best Wishes
Ro
bject to a constant power factor constraint, then you
> will need to supply an additional user-defined linear constraint. For
> example, if you want to run case9 with a constant power factor constraint of
> 0.95 on the first generator, you could do it like this ...
>
> define_constant
Dirk's suggestion is fine for a simple power flow. But if you want to run an OPF, where the generator dispatch is to be determined by the optimization, but subject to a constant power factor constraint, then you will need to supply an additional user-defined linear constraint. For example, i
Roberto
On Fri, Mar 11, 2011 at 12:22, Dirk Van Hertem
mailto:dirk.vanher...@ieee.org>> wrote:
You can just define them as a PQ bus with negative power...
(negative load)
Dirk
On 03/11/2011 12:11 PM, Roberto Carvalini wrote:
Hi
How can I define constant
; Hi
>>
>> How can I define constant power factor in MAPOWER for example, for
>> generators PF=0.9?
>>
>> Please help me
>>
>> Regards
>>
>> Roberto
>>
>>
>>
>
> --
> Dirk Van Hertem dirk.vanher...@
You can just define them as a PQ bus with negative power... (negative load)
Dirk
On 03/11/2011 12:11 PM, Roberto Carvalini wrote:
Hi
How can I define constant power factor in MAPOWER for example, for
generators PF=0.9?
Please help me
Regards
Roberto
--
Dirk Van Hertem
Hi
How can I define constant power factor in MAPOWER for example, for
generators PF=0.9?
Please help me
Regards
Roberto
Thanks.
On Fri, Mar 4, 2011 at 16:24, Ray Zimmerman wrote:
> For a dispatchable load with a positive reactive load, QMIN and PMIN are
> used to compute the constant power factor constraint. QG and PG must also be
> consistent with this power factor. If you adjust any of these 4 p
For a dispatchable load with a positive reactive load, QMIN and PMIN are used
to compute the constant power factor constraint. QG and PG must also be
consistent with this power factor. If you adjust any of these 4 parameters, you
must adjust the others to ensure that QMIN/PMIN = QG/PG. If the
Hello
How can I change power factor of dispatchable loads (changing reactive power
) in MATPOWER? I cannot change. there is an error
Regards
Hello
How can I change power factor of dispatchable loads (changing reactive power
) in MATPOWER? I cannot change. there is an error
Regards
ower 3.2. When using 'uopf' , can power factor of certain generators remain constant, for example , power factor is set to 0.85 ? I added a linear constraint (A,l,u) to 'opf', but failed. The linear constraint is : l<=Ax<=u Ax=Pg - 0.61*Qg, l=0, u=0. (be
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