-- Ray Zimmerman Senior Research Associate 211 Warren Hall, Cornell University, Ithaca, NY 14853 phone: (607) 255-9645
On Mar 14, 2011, at 12:16 PM, Carlos Gonzalez Almeida wrote: With more details I want to do runmarket and I want to have PF=0.85 for example in case9 for generators 2, 3. How can I do it?
Best Wishes
C. Gonzalez Almeida
On Mon, Mar 14, 2011 at 17:10, Carlos Gonzalez Almeida <[email protected]> wrote:
Thank you. I also have the Roberto's problem as well as in the case of runmarket to set an specified power factor for generators except slack bus. If it is possible please give an example. Because it can be useful for other people who will use in the future MATPOWER.
Best Wishes
C. Gonzalez Almeida
On Mon, Mar 14, 2011 at 16:59, Ray Zimmerman <[email protected]> wrote:
1. You can constrain a generator to have a zero power factor by setting PMIN = PMAX = 1. The generator reactive power is one of the optimization variables in x, so it's value is determined by whatever solver you happen to be using, MIPS by default. So I suppose if you need to know which m-file computes its value, it would be mips.m. If you want to set the reactive power of generator 2 to zero, simply set both the QMIN and QMAX column in the corresponding row of the gen matrix to zero (by the way, that is a power factor of 1, not 0).
Without more details I have no idea. Are you passing in any reactive power offers?
-- Ray Zimmerman Senior Research Associate 211 Warren Hall, Cornell University, Ithaca, NY 14853
On Mar 14, 2011, at 6:17 AM, Carlos Gonzalez Almeida wrote: Dear Prof. Zimmerman
1.I studied the your response to Roberto Carvalini but I don't know how can I define the PF for other generators to zero or other values when I do runmarket and it doesn't work the code when I do runmarket. By which formula you have computed the generator reactive power (in which m.file, please address the m.file because I couldn't find it). For example, if I want to set reactive power of generator 2 to zero, what should I do?
2. Why I cannot do runmarket for case30Q and case9Q? what is the reason?
Best Wishes
C. Gonzalez Almeida
On Fri, Mar 11, 2011 at 16:29, Ray Zimmerman <[email protected]> wrote:
See my response to Roberto Carvalini, posted only seconds ago. Am I fast or what? ;-)
-- Ray Zimmerman Senior Research Associate 211 Warren Hall, Cornell University, Ithaca, NY 14853
On Mar 11, 2011, at 10:16 AM, Carlos Gonzalez Almeida wrote: Thank you very much. Could you please give me an example about defining power factor for generators?
I cannot set it. On Fri, Mar 11, 2011 at 16:09, Ray Zimmerman <[email protected]> wrote:
Carlos,
If you want the loads to have a power factor of 0.95, you need to set QD such that PD/sqrt(PD^2 + QD^2) = 0.95, i.e. QD has to equal 0.108 * PD. About the voltage constraint of 1.5 p.u., I don't see that anywhere, so I'm not sure what you are referring to. The different lambdas at the two buses are due to losses. The power factor of the generators is determined by the solution algorithm within the bounds set for them. That is, each generator has a feasible "box" defined by PMIN, PMAX, QMIN and QMAX. You don't normally "set" the power factor of a generator as input to the OPF. I suppose, if for some reason you have a strict power factor constraint on a generator you could use some additional linear constraints to the OPF to enforce it, but that would be unusual I think.
--
Ray Zimmerman Senior Research Associate 211 Warren Hall, Cornell University, Ithaca, NY 14853
On Mar 10, 2011, at 8:10 AM, Carlos Gonzalez Almeida wrote: Another question is this: when I have not fixed loads only I have dispatchable loads how can I define power factor for generators and loads separately?
Best Wishes
Carlos On Thu, Mar 10, 2011 at 13:53, Carlos Gonzalez Almeida <[email protected]> wrote:
Dear Prof. Zimmerman Thanks a lot for your useful guidance. For example, in the attached file for a simple case study with 2 loads and generators I want to have a power factor 0.95. I have problem with adjusting power factor in MATPOWER. How can I do it in the attached file? Also I don't know why I have voltage constraint 1.5 pu. I think because of these constraints I have a little bit difference in the value of lambda
I have done runmarket with the following offers and bids. Could you please tell me why? +++++++++++++++++++++ mpc0 = loadcase('case4gs1'); mpc = load2disp(mpc0); mkt.OPF = 'AC'; offers.P.qty = [100;70];
offers.P.prc = [50;100]; bids.P.qty = [50 ;70 ]; bids.P.prc = [150 ;130 ]; [r, co, cb] = runmarket(mpc, offers, bids, mkt); co.P.qty co.P.prc cb.P.qty cb.P.prc ++++++++++++++++++++++++
Best Wishes
C. Gonzalez Almeida On Wed, Mar 9, 2011 at 19:47, Ray Zimmerman <[email protected]> wrote:
Carlos,
I'm not sure what you mean by "test the example ... regarding zero power factor". If you are going to change some of the existing dispatchable loads to have a zero power factor, then the existing market structure for the example, which includes only $/MW bids for active power, will not be applicable. So you need to decide how you want to handle these reactive-only loads. I suppose you'll need to specify reactive power bids for them.
On your second question, the offers and bids are used to construct a gencost matrix with negative costs for the negative generators that represent dispatchable loads. The objective function is then to minimize this "cost" of generation, which is computed in opf_costfcn.m. You are correct that this is equivalent to maximizing social welfare.
--
Ray Zimmerman Senior Research Associate 211 Warren Hall, Cornell University, Ithaca, NY 14853
On Mar 8, 2011, at 5:04 PM, Carlos Gonzalez Almeida wrote: Dear Dr. Zimmerman -Could you please test the example provided in the manual (t_auction_case) regarding zero power factor. What changes should be carried out?
-Moreover, as you know, the objective function obtained in the runmarket is Social welfare. Could you please address me the file that you calculated objective function because I couldn't find it. I want to know in which file (the m file) you have calculated that?
Best Regards Carlos On Tue, Mar 8, 2011 at 22:34, Ray Zimmerman <[email protected]> wrote:
I'm not really sure without seeing the details of your example. I'm not sure I've ever tested the runmarket code with pure reactive power loads. It would require reactive power bids for those loads, but I'll need the details to be able to help you further.
-- Ray Zimmerman Senior Research Associate 211 Warren Hall, Cornell University, Ithaca, NY 14853
On Mar 7, 2011, at 10:42 AM, Carlos Gonzalez Almeida wrote: Hi
I am new in MATPOWER abd I want to have zero power factor for example in example case of manual in runmarket, but several error are occured. please tell me why
Best Wishes
C. Gonzalez Almeida
Best Wishes
C. Gonzalez Almeida
Best Wishes
C. Gonzalez Almeida
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pf_constraint_eg.m