Thank you very much for your guidance. I solved the problem.

Best Regards

Carlos

On Wed, Mar 16, 2011 at 23:28, Ray Zimmerman <[email protected]> wrote:

> No, it doesn't make sense to have bids without dispatchable loads. What
> would the bids correspond to if there are no dispatchable resources on the
> demand side of the market?
>
> Again, to me, specifying the power factor for everything doesn't make
> sense. But if you insist, then you'll have to do what I said before, create
> an A matrix with constant power factor constraints for the actual generators
> only, not including the dispatchable loads (which already have their own
> constant power factor constraints created automatically by MATPOWER).
>
>  --
> Ray Zimmerman
> Senior Research Associate
> 211 Warren Hall, Cornell University, Ithaca, NY 14853
> phone: (607) 255-9645
>
>
>
> On Mar 16, 2011, at 12:25 PM, Carlos Gonzalez Almeida wrote:
>
> Yes. without converting loads to dispatchable loads is it possible to
> insert bids? if yes how?
>
> my problem is this, with only offers I can do runmarket but with both
> offers and bids I cannot do runmarket with specified PF. How can I do this?
>
> On Wed, Mar 16, 2011 at 17:21, Ray Zimmerman <[email protected]> wrote:
>
>> It doesn't matter what the power factor is, you cannot give two
>> conflicting power factor constraints for a dispatchable load. There is one
>> that is created automatically by MATPOWER from the Q/P ratio of the load (
>> QMIN/PMIN) and the other you are adding explicitly. If the one you
>> specify explicitly is different from the one automatically created by
>> MATPOWER, then you have made the problem infeasible and it will not work. If
>> they are the same then you have added redundant constraints that could
>> potentially cause numerical issues.
>>
>> So, for loads, set the power factor directly by setting the P and Q in the
>> bus matrix (or gen matrix if you are not using load2disp) and do not add
>> explicit power factor constraints via the *A* matrix.
>>
>>  --
>> Ray Zimmerman
>> Senior Research Associate
>> 211 Warren Hall, Cornell University, Ithaca, NY 14853
>> phone: <%28607%29%20255-9645>(607) 255-9645
>>
>>
>>
>> On Mar 16, 2011, at 12:00 PM, Carlos Gonzalez Almeida wrote:
>>
>> Thank you very much for your help.
>>
>> for any power factor(0.85,0.95,0.9, ....) I have this problem. The value
>> of PF is not important for me. The important thing is that I cannot do
>> runmarket with the specified power factor as I want.
>>
>> Best Regards
>>
>> Carlos
>>
>> On Wed, Mar 16, 2011 at 16:51, Ray Zimmerman <[email protected]> wrote:
>>
>>> The problem here is that you've made the problem infeasible by adding
>>> conflicting constraints. Remember, dispatchable loads are implemented as
>>> generators (with PMAX = 0 and PMIN < 0). Each dispatchable load already has
>>> a constant power factor constraint, included automatically by MATPOWER, that
>>> keeps the Q/P ratio equal to the original ratio. This ratio is not zero for
>>> the loads in case9, but you have added another constraint to these
>>> "generators" trying to force the power factor to equal 1 (Q/P ratio = 0) and
>>> these constraints conflict. You need to modify *A*, *l* and *u*, to only
>>> include rows for the original generators, not the dispatchable loads. Check
>>> out the isload function to help you find which are the real gens.
>>>
>>> I still question why forcing the power factor to equal 1 for all
>>> generators except the reference gen is so important to you. Are any real
>>> power systems ever operated under such constraints?
>>>
>>>  --
>>> Ray Zimmerman
>>> Senior Research Associate
>>> 211 Warren Hall, Cornell University, Ithaca, NY 14853
>>> phone: <%28607%29%20255-9645> <%28607%29%20255-9645>(607) 255-9645
>>>
>>>
>>>
>>> On Mar 16, 2011, at 7:04 AM, Carlos Gonzalez Almeida wrote:
>>>
>>> Dear Prof. Zimmerman
>>>
>>> I want to do runmarket with following offers and bids also with PF=1 for
>>> generators and the following error is occurred.
>>> Could you please help me?
>>>
>>> *define_constants;
>>> mpc0= loadcase('case9');
>>> mpc = load2disp(mpc0);
>>> offers.P.qty = [200; 150; 180];
>>> offers.P.prc = [30; 40; 50];
>>> bids.P.qty = [70; 70; 70];
>>> bids.P.prc = [100; 90; 80];
>>> mkt.OPF = 'AC';
>>> nb = size(mpc.bus, 1);
>>> ng = size(mpc.gen, 1);
>>> pf = 1;
>>> 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:end, :);
>>> mpc.l = zeros(ng-1, 1);
>>> mpc.u = mpc.l;
>>> [r, co, cb] = runmarket(mpc, offers, bids, mkt);*
>>>
>>> Results
>>>
>>> *Warning: Matrix is singular to working precision.
>>> > In mips at 422
>>>   In mipsopf_solver at 145
>>>   In opf_execute at 106
>>>   In opf at 225
>>>   In uopf at 154
>>>   In smartmkt at 90
>>>   In runmarket at 141
>>> Warning: Matrix is singular to working precision.
>>> > In mips at 422
>>>   In mipsopf_solver at 145
>>>   In opf_execute at 106
>>>   In opf at 225
>>>   In uopf at 154
>>>   In smartmkt at 90
>>>   In runmarket at 141
>>>
>>> SMARTMARKET: non-convergent UOPF??? Error using ==> mtimes
>>> Inner matrix dimensions must agree.
>>>
>>> Error in ==> smartmkt at 170
>>>     price       = mkt.lim.P.max_offer * ones(ng, 1);
>>>
>>> Error in ==> runmarket at 141
>>> [co, cb, r, dispatch, success] = smartmkt(mpc, offers, bids, mkt, mpopt);
>>> *
>>>
>>> Best Wishes
>>>
>>> Carlos
>>>
>>>
>>>
>>
>>
>> Best Wishes
>>
>> C. Gonzalez Almeida
>>
>>
>>
>
>
> Best Wishes
>
> C. Gonzalez Almeida
>
>
>


Best Wishes

C. Gonzalez Almeida

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