That suffices..thank you sir
On Wednesday, 8 January 2014 8:50 AM, Ray Zimmerman <r...@cornell.edu> wrote:
Generation = load + losses, so if you can dispatch the system (including
reactive power and voltage) in a way the reduces losses, you also reduce the
total generation. Defining the problem formulation that is “better” always
depends on your application and the resources available for dispatch. Allowing
the power factor to vary certainly increases flexibility potentially increasing
your ability to make use of lower cost resources.
--
Ray Zimmerman
Senior Research Associate
B30 Warren Hall, Cornell University, Ithaca, NY 14853
phone: (607) 255-9645
On Jan 7, 2014, at 10:43 AM, AMAN BANSAL <amanb1...@yahoo.com> wrote:
Dear Sir,
>
>
>How this flexibility would actually have an impact on the generation output.
>In OPF, under both the cases, generator output should be same.
>And Sir, is it better to run system under variable pf scenario because that
>would lead to reduced cost and losses or their are some compromises that are
>to be made ?
>
>
>
>On Tuesday, 7 January 2014 7:27 PM, Ray Zimmerman <r...@cornell.edu> wrote:
>
>I believe both of your questions have the same answer: When you allow more
>flexibility in the system (increased range of generator voltages or variable
>power factor) there are more degrees of freedom to use to reduce costs. In
>particular, there is more flexibility that can be used to minimize losses,
>resulting in a decrease in overall generator output.
>
>
>--
>Ray Zimmerman
>Senior Research Associate
>B30 Warren Hall, Cornell University, Ithaca, NY 14853
>phone: (607) 255-9645
>
>
>
>
>On Jan 7, 2014, at 5:59 AM, Carlos Gonzalez Almeida
><cgonzalezalme...@gmail.com> wrote:
>
>Dear Dr. Zimmerman,
>>
>>
>>When I am running an OPF considering two cases;
>>
>>
>>1) Fixed power factor
>>2) variable power factor
>>
>>
>>in (1) the total output power of generators are higher than that obtained in
>>(2). But It should be vice versa conceptually, i.e. it should be higher in
>>case (2). Could you please let me know what is the reason?
>>
>>
>>The following codes have been used to obtain the results.
>>
>>
>>(1)
>>
>>
>>define_constants;
>>mpc = loadcase('case9');
>>nb = size(mpc.bus, 1);
>>ng = size(mpc.gen, 1);
>>pf = 0.85;
>>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);
>>**************************************************
>>
>>
>>(2)
>>
>>
>>define_constants;
>>mpc = loadcase('case9');
>>r = runopf(mpc);
>>
>>****************************************
>>
>>
>>According to abovementioned codes
>>
>>
>>
>>
>>Best regards,
>>
>>
>
>
>
