Maybe you missed my response ... simply use a different mpc for each hour ...
suppose you have a 24 x 1 vector load_multiplier with the load multiplier
(factor to multiply the nominal load) for each of the 24 hours. Then you would
run 24 different load flows as follows ...
mpc0 = loadcase('case118');
for t = 1:24
mpc(t) = mpc0;
mpc(t).bus = scale_load(load_multiplier(t), mpc(t).bus);
results(t) = runpf(mpc(t));
end
Hope this helps,
--
Ray Zimmerman
Senior Research Associate
419A Warren Hall, Cornell University, Ithaca, NY 14853
phone: (607) 255-9645
On Jun 11, 2012, at 7:10 AM, iman wrote:
> Dear All,
> I have a question regarding load variation.It has been discussed and explain
> a few times and Dr Carlos and has included the code as seen at the bottom of
> this post;however, there is one ambiguous point in it.
> Having a load profile in 24 hours as
> 6 hours (0.6 * peak load)
> 2 hours (1 peak load)
> 16 hours (0.8 peak load)
> If i want to have a Power flow in 24 hours(?can we have power flow for a
> period of time?) should I write the code as:
> mpc = loadcase('case118');
> define_constants;
> Nominal_PD = mpc.bus(:, PD);
> Nominal_QD = mpc.bus(:, QD):
>
> mpc.bus(:, PD) = 0.6 * Nominal_PD;
> mpc.bus(:, QD) = 0.6 * Nominal_QD;
> mpc.bus(:, PD) = 1 * Nominal_PD;
> mpc.bus(:, QD) = 1 * Nominal_QD;
> mpc.bus(:, PD) = 0.8 * Nominal_PD;
> mpc.bus(:, QD) = 0.8 * Nominal_QD;
> results = runpf(mpc);
> If yes, how different durations are considered ?(2 hours,6 hours,16 hours)
> Thank you
> Iman
> -------------------------------
> On Fri, May 18, 2012 at 9:01 PM, Carlos E Murillo-Sanchez
> <[email protected]> wrote:
> There is a rather flexible utility in matpower for scaling loads. Type
> >> help scale_load
>
> at the matlab prompt for help on how to use it. Otherwise, if you just want
> to modify inflexible demand,
> you could do something like
>
> mpc = loadcase('case118');
> define_constants;
> Nominal_PD = mpc.bus(:, PD);
> Nominal_QD = mpc.bus(:, QG):
> for factor = 0.8:0.01:1.20
> mpc.bus(:, PD) = factor * Nominal_PD;
> mpc.bus(:, QD) = factor * Nominal_QD;
> results = runpf(mpc);
> % now insert code here to do whatever you want to do with the results
> your code....
> more code...
> end
>
> This scales inflexible demand in the system by a factor from 80% of nominal
> to 120% of nominal in 1% increments and runs a power flow; you could run also
> an optimal power flow using runopf() instead. The load is scaled
> maintaining a constant power factor.
>
>
>
>
>
> Hanie Sedghi wrote:
> Dear Sir,
>
> I would like to have different voltage angle values at different times for a
> structure. Let's say I want to have the same structure as case9, but I want
> to know what are the values at different times. It is like simulating a grid
> and taking samples at different times. For that I think I need different
> demands. Then I checked the case file and thought I need to put random Pg's
> in "gen" matrix. Am I right? Shall I generate random values in [Pmin,Pmax]
> interval?
> I have another question, in case9, for bus 1, Pg=0 while Pmin=10. Is it
> correct? Can Pg be less than Pmin? In that case,what do we mean by Pmin?
>
> I would truly appreciate your help.
>
> Best,
> Hanie
>
>
>
>
>
> --
> Best regards
> Iman
>
