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] > <mailto:[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] <mailto:[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] >> <mailto:[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] <mailto:[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; >> >> > >
