What problem are you trying to solve? If you don’t have an objective function
then the OPF is probably not the right tool. Unless there is a unique feasible
solution, you need some way of ranking the typically infinite number of
feasible solutions so it can give you an “optimal” one.
Ray
> On Feb 23, 2017, at 2:20 PM, BRENDA ROJAS DELGADO <[email protected]> wrote:
>
> Hi, Ray:
>
> I have the same issue. My grid is being studied with OPF and even tough I
> knew from the beginning that gencost matrix cannot be supressed at all, I
> have tried to assume that gencost=0 in order to not take into count any cost
> so far.
>
> But Matpower doesn't accept gencost=0 and I don't know why. I would like to
> have a solution to my problem because when I use Matpower with a Optimization
> Tool belonging whether to Matlab or Opti Toolbox, it takes too long the
> computation time and that's an advantage I would like to keep on taking of
> when running an OPF.
>
> Thanks is advance for the reply. Best regards
>
> Brenda Rojas
>
>
>
> El jueves, 23 de febrero de 2017, Ray Zimmerman <[email protected]
> <mailto:[email protected]>> escribió:
> The OPF (and the problem solved by MOST) are optimization problems, which
> means they are attempting to minimize some cost subject to constraints. So,
> no, you can’t eliminate the cost function. If you aren’t trying to minimize a
> cost, I’m not sure that MOST or OPF are the right tools.
>
> And, by the way, the error you are seeing appears to be related to
> dispatchable loads (which also make no sense without a corresponding benefit
> or “cost”).
>
> Ray
>
>
>> On Feb 21, 2017, at 7:03 AM, Alberto Claudio Alvisi
>> <[email protected]
>> <javascript:_e(%7B%7D,'cvml','[email protected]');>> wrote:
>>
>> Hi,
>>
>> I've just written saturday about my problem:
>>
>>
>> "Dear all,
>>
>> I'm working on my thesis using MATPOWER, but I' ve this problem with MOST
>> tool:
>>
>> Error using .*
>> Matrix dimensions must agree.
>>
>> Error in most (line 2116)
>> mpc.gen(ivl, QG) = mpc.gen(ivl, PG) .* Qlim ./ Pmin(ivl);
>>
>> In particular:
>>
>> Qlim =
>>
>> []
>>
>> mpc.gen(ivl, PG)
>>
>> ans =
>>
>> Empty matrix: 0-by-1."
>>
>>
>> After I've read more documentation about MATPOWER and MOST tool, I
>> understand that the OPF solution required to find the min f(x) with a
>> constraint of cost.
>> I've a case without gencost and I prefer to not create a gencost matrix to
>> solve it because the cost of PG don't matter in my case.
>> It's possible to impose that MATPOWER doesn't study the cost of PG during
>> the solution process? In other words, is there a MATPOWER option to leave
>> the cost constraint?
>>
>> Thanks a lot for your contribution
>>
>> Regards
>>
>>
>> ALBERTO CLAUDIO ALVISI
>> Student at University Of Bologna
>
