Dear Dr. Zimmerman, I want to set PF between 0.8 and 0.9 for all generators. I have changed A as follows and I am not sure whether it is true or not. It always gives last PF. I don't know why? *mpc.A = sparse([1:ng 1:ng **1:ng 1:ng**]', [2*nb+(1:ng) 2*nb+ng+(1:ng) **2*nb+(1:ng) 2*nb+ng+(1:ng)**]', [QPratio1*ones(ng,1); -ones(ng,1), **QPratio2*ones(ng,1); -ones(ng,1)**], ng, 2*nb+2*ng**, ng, 2*nb+2*ng**)* *mpc.A = mpc.A(2:end, :);* *mpc.l = zeros(ng-1, 1);* *mpc.u = mpc.l;*
Best Wishes Roberto On Mon, Feb 6, 2012 at 22:03, Ray Zimmerman <[email protected]> wrote: > You simply replace the single equality constraint (per gen) with two > inequality constraints with the two corresponding QPratio values. > > pf1 = 0.8; > pf2 = 0.9; > QPratio1 = sqrt(1/pf1^2 -1); > QPratio2 = sqrt(1/pf2^2 -1); > % then write the constraints for > % QPratio1 * Pg(i) - Qg(i) > 0 > % QPratio2 * Pg(i) - Qg(i) < 0 > > I don't have time to work out the details for 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: > > 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 variable PF between 0.8 and 0.9. > > *define_constants;* > *mpc = loadcase('case9');* > *nb = size(mpc.bus, 1);* > *ng = size(mpc.gen, 1);* > *pf = 0.95;* > *QPratio = sqrt(1/pf^2 -1);* > *%% add constraint that QPratio * Pg(i) - Qg(i) = 0, for i = 2 .. ng* > *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:end, :);* > *mpc.l = zeros(ng-1, 1);* > *mpc.u = mpc.l;* > *r = runopf(mpc);* > > Regards > > Roberto > > > > > > > >
