Dear Dr. Zimmerman, Thank you. It gives the same results as before. Nothing is changed. I want to replace zero "0" in upper and lower limits with -0.95 and 0.95 (*-0.95 <= QPratio * Pg(i) - Qg(i) <= 0.95*). I know what is power factor. If possible, please help me. I will be very grateful.
In previous post you explained it as follow: *"The A matrix is from equation (5.25) in the User's Manual, where x is defined in (5.5). So as it says in the example code I provided you, the constraint we want to implement is ... 0 <= QPratio * Pg(i) - Qg(i) <= 0This is an equality constraint that forces a constant ratio between Qg(i) and Pg(i), in other words, a constant power factor. So we need to define A such that A * x = QPratio * Pg(i) - Qg(i), which means that A needs to have QPratio in the column corresponding to Pg(i) and -1 in the column corresponding to Qg(i). If you look at equation (5.5), you'll see that Pg(i) is found in element (2*nb + i) of x and Qg(i) in element (2*nb+ng+i). The sparse statement constructs this A matrix, and l and u from (5.25) are set to zero."* Best regards, On Mon, Mar 14, 2011 at 5:59 PM, Ray Zimmerman <[email protected]> wrote: > Did you understand the previous example? If so, it's a trivial > modification (attached). If not, please go back and familiarize yourself > with the extended OPF formulation in the manual, the paper, the slides for > the paper, etc. This is about the most trivial example can think of for > adding a user-defined constraint to the OPF. > > > > -- > 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 >>> phone: <%28607%29%20255-9645>(607) 255-9645 >>> >>> >>> >>> 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 >>>> phone: <%28607%29%20255-9645> >>>> <%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645>(607) >>>> 255-9645 >>>> >>>> >>>> >>>> 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 >>>>> phone: <%28607%29%20255-9645> >>>>> <%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645>(607) >>>>> 255-9645 >>>>> >>>>> >>>>> >>>>> 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 >>>>>>> phone: <%28607%29%20255-9645> >>>>>>> <%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645>(607) >>>>>>> 255-9645 >>>>>>> >>>>>>> >>>>>>> >>>>>>> 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 >>>>>>>> phone: <%28607%29%20255-9645> >>>>>>>> <%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645>(607) >>>>>>>> 255-9645 >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> 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 >>>> >>>> >>>> >>> >>> >>> >> > > >
