Dear Dr. Zimmerman, What modifications I have to apply to the following code? Thanks
*ng = size(mpc.gen, 1);* >> *pf = 0.95;* >> *QPratio = sqrt(1/pf^2 -1);* >> >> *mpc.A = sparse([1:ng 1:ng]', [2*nb+(1:ng) 2*nb+ng+(1:ng)]', >> [QPratio*ones(ng,1); -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 <[email protected]> wrote: > 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 Marta Gonzalez Almeida < > [email protected]> wrote: > > My problem is that I cannot implement matrix A in order to have > -0.95*P<Q<P*0.95. What changes I have to apply to A matrix? > > Regards, > > Carlos > > On Mon, Sep 21, 2015 at 3:43 PM, Ray Zimmerman <[email protected]> wrote: > >> You really do need to understand what that code is doing before you can >> make modifications to make it do something else. So, to repeat my main >> question … is there a particular part of that code that 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 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 should be trivial to get rid of the appropriate bound ( >> *l* or *u*) to change it to an upper or lower bound on the power factor. >> Then you add a similar and opposite bound for another power factor value >> for the other end of your range. >> >> But, as I said … the first step is to fully understand the example you >> have. >> >> Ray >> >> >> >> On Sep 21, 2015, at 2:37 AM, Carlos Marta Gonzalez Almeida < >> [email protected]> wrote: >> >> DEar Dr. Zimmerman, >> >> I don't know how I should change the equality constraint to inequality >> constraint. I'll be very grateful if you can help me. >> >> Best regards, >> >> Carlos >> >> On Fri, Sep 18, 2015 at 4:12 PM, Ray Zimmerman <[email protected]> wrote: >> >>> *Please address MATPOWER support questions (including followup’s to this >>> e-mail) to the MATPOWER mailing list >>> <http://www.pserc.cornell.edu/matpower/#mailinglist>.* >>> >>> You simply have to change the equality constraint to an inequality >>> constraint. Is there a particular part of that code snippet that you are >>> having trouble understanding? >>> >>> Ray >>> >>> >>> On Sep 1, 2015, at 11:58 AM, Carlos Marta Gonzalez Almeida < >>> [email protected]> wrote: >>> >>> Dear Dr. Zimmerman, >>> >>> According to your previous posts on the following equation which makes >>> the power factor constant. Now I want to have power factor varying between >>> -0.95 and 0.95. What changes to the following equation to be made? >>> >>> Thank you very much. >>> >>> Carlos >>> >>> >>> >>> *ng = size(mpc.gen, 1);* >>> *pf = 0.95;* >>> *QPratio = sqrt(1/pf^2 -1);* >>> >>> *mpc.A = sparse([1:ng 1:ng]', [2*nb+(1:ng) 2*nb+ng+(1:ng)]', >>> [QPratio*ones(ng,1); -ones(ng,1)], ng, 2*nb+2*ng);* >>> >>> *mpc.A = mpc.A(2:10, :);* >>> *mpc.l = zeros(ng-15, 1);* >>> *mpc.u = mpc.l;* >>> >>> >>> >> >> > >
