Dear Prof. Zimmerman

Once again I appreciate you for the file that you sent me. Where can I find
more information about the way of definition of A matrix. I have read the
manual but I didn't understand well, for example in the case you sent me
yesterday. If it is possible either please introduce me a book or explain a
little bit more about A matrix in general.

Best Wishes

C. Gonzalez Almeida


On Mon, Mar 14, 2011 at 19:05, Carlos Gonzalez Almeida <
[email protected]> wrote:

> Thank you very very much.
>
> On Mon, Mar 14, 2011 at 18:59, Ray Zimmerman <[email protected]> wrote:
>
>> Did you understand the previous example? If so, it's a trivial
>> modification (attached). If not, please go back and familiarize yourself
>> with the extended OPF formulation in the manual, the paper, the slides for
>> the paper, etc. This is about the most trivial example can think of for
>> adding a user-defined constraint to the OPF.
>>
>>
>>
>>  --
>> 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 14, 2011, at 12:16 PM, Carlos Gonzalez Almeida wrote:
>>
>> With more details I want to do runmarket and I want to have PF=0.85 for
>> example in case9 for generators 2, 3. How can I do it?
>>
>> Best Wishes
>>
>> C. Gonzalez Almeida
>>
>>
>> On Mon, Mar 14, 2011 at 17:10, Carlos Gonzalez Almeida <
>> [email protected]> wrote:
>>
>>> Thank you.
>>>
>>> I also have the Roberto's problem as well as in the case of runmarket to
>>> set an specified power factor for generators except slack bus.
>>>
>>> If it is possible please give an example. Because it can be useful for
>>> other people who will use in the future MATPOWER.
>>>
>>> Best Wishes
>>>
>>> C. Gonzalez Almeida
>>>
>>>
>>> On Mon, Mar 14, 2011 at 16:59, Ray Zimmerman <[email protected]> wrote:
>>>
>>>> 1. You can constrain a generator to have a zero power factor by setting
>>>> PMIN = PMAX = 1. The generator reactive power is one of the
>>>> optimization variables in *x*, so it's value is determined by whatever
>>>> solver you happen to be using, MIPS by default. So I suppose if you need to
>>>> know which m-file computes its value, it would be mips.m. If you want
>>>> to set the reactive power of generator 2 to zero, simply set both the
>>>> QMIN and QMAX column in the corresponding row of the gen matrix to zero
>>>> (by the way, that is a power factor of 1, not 0).
>>>>
>>>> Without more details I have no idea. Are you passing in any reactive
>>>> power offers?
>>>>
>>>>  --
>>>> Ray Zimmerman
>>>> Senior Research Associate
>>>> 211 Warren Hall, Cornell University, Ithaca, NY 14853
>>>> phone: <%28607%29%20255-9645> 
>>>> <%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645>(607)
>>>> 255-9645
>>>>
>>>>
>>>>
>>>> On Mar 14, 2011, at 6:17 AM, Carlos Gonzalez Almeida wrote:
>>>>
>>>> Dear Prof. Zimmerman
>>>>
>>>> 1.I studied the your response to Roberto Carvalini but I don't know how
>>>> can I define the PF for other generators to zero or other values when I do
>>>> runmarket and it doesn't work the code when I do runmarket. By which 
>>>> formula
>>>> you have computed the generator reactive power (in which m.file, please
>>>> address the m.file because I couldn't find it). For example, if I want to
>>>> set reactive power of generator 2 to zero, what should I do?
>>>>
>>>> 2. Why I cannot do runmarket for case30Q and case9Q? what is the reason?
>>>>
>>>>
>>>> Best Wishes
>>>>
>>>> C. Gonzalez Almeida
>>>>
>>>>
>>>> On Fri, Mar 11, 2011 at 16:29, Ray Zimmerman <[email protected]> wrote:
>>>>
>>>>> See my response to Roberto Carvalini, posted only seconds ago. Am I
>>>>> fast or what?  ;-)
>>>>>
>>>>>  --
>>>>> Ray Zimmerman
>>>>> Senior Research Associate
>>>>> 211 Warren Hall, Cornell University, Ithaca, NY 14853
>>>>> phone: <%28607%29%20255-9645> 
>>>>> <%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645>(607)
>>>>> 255-9645
>>>>>
>>>>>
>>>>>
>>>>> On Mar 11, 2011, at 10:16 AM, Carlos Gonzalez Almeida wrote:
>>>>>
>>>>> Thank you very much.
>>>>>
>>>>> Could you please give me an example about defining power factor for
>>>>> generators?
>>>>>
>>>>> I cannot set it.
>>>>>
>>>>> On Fri, Mar 11, 2011 at 16:09, Ray Zimmerman <[email protected]> wrote:
>>>>>
>>>>>> Carlos,
>>>>>>
>>>>>> If you want the loads to have a power factor of 0.95, you need to set
>>>>>> QD such that PD/sqrt(PD^2 + QD^2) = 0.95, i.e. QD has to equal 0.108 * 
>>>>>> PD.
>>>>>> About the voltage constraint of 1.5 p.u., I don't see that anywhere, so 
>>>>>> I'm
>>>>>> not sure what you are referring to. The different lambdas at the two 
>>>>>> buses
>>>>>> are due to losses. The power factor of the generators is determined by 
>>>>>> the
>>>>>> solution algorithm within the bounds set for them. That is, each 
>>>>>> generator
>>>>>> has a feasible "box" defined by PMIN, PMAX, QMIN and QMAX. You don't
>>>>>> normally "set" the power factor of a generator as input to the OPF. I
>>>>>> suppose, if for some reason you have a strict power factor constraint on 
>>>>>> a
>>>>>> generator you could use some additional linear constraints to the OPF to
>>>>>> enforce it, but that would be unusual I think.
>>>>>>
>>>>>> --
>>>>>>  Ray Zimmerman
>>>>>> Senior Research Associate
>>>>>> 211 Warren Hall, Cornell University, Ithaca, NY 14853
>>>>>> phone: <%28607%29%20255-9645> 
>>>>>> <%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645>(607)
>>>>>> 255-9645
>>>>>>
>>>>>>
>>>>>>
>>>>>> On Mar 10, 2011, at 8:10 AM, Carlos Gonzalez Almeida wrote:
>>>>>>
>>>>>> Another question is this: when I have not fixed loads only I have
>>>>>> dispatchable loads how can I define power factor for generators and loads
>>>>>> separately?
>>>>>>
>>>>>> Best Wishes
>>>>>>
>>>>>> Carlos
>>>>>>
>>>>>> On Thu, Mar 10, 2011 at 13:53, Carlos Gonzalez Almeida <
>>>>>> [email protected]> wrote:
>>>>>>
>>>>>>> Dear Prof. Zimmerman
>>>>>>>
>>>>>>> Thanks a lot for your useful guidance.
>>>>>>>
>>>>>>> For example, in the attached file for a simple case study with 2
>>>>>>> loads and generators I want to have a power factor 0.95. I have problem 
>>>>>>> with
>>>>>>> adjusting power factor in MATPOWER. How can I do it in the attached 
>>>>>>> file?
>>>>>>> Also I don't know why I have voltage constraint 1.5 pu. I think because 
>>>>>>> of
>>>>>>> these constraints I have a little bit difference in the value of lambda
>>>>>>> I have done runmarket with the following offers and bids.
>>>>>>> Could you please tell me why?
>>>>>>>
>>>>>>> +++++++++++++++++++++
>>>>>>> mpc0 = loadcase('case4gs1');
>>>>>>> mpc = load2disp(mpc0);
>>>>>>> mkt.OPF = 'AC';
>>>>>>> offers.P.qty = [100;70];
>>>>>>> offers.P.prc = [50;100];
>>>>>>> bids.P.qty = [50 ;70 ];
>>>>>>> bids.P.prc = [150 ;130 ];
>>>>>>> [r, co, cb] = runmarket(mpc, offers, bids, mkt);
>>>>>>> co.P.qty
>>>>>>> co.P.prc
>>>>>>> cb.P.qty
>>>>>>> cb.P.prc
>>>>>>> ++++++++++++++++++++++++
>>>>>>>
>>>>>>> Best Wishes
>>>>>>>
>>>>>>> C. Gonzalez Almeida
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> On Wed, Mar 9, 2011 at 19:47, Ray Zimmerman <[email protected]>wrote:
>>>>>>>
>>>>>>>> Carlos,
>>>>>>>>
>>>>>>>> I'm not sure what you mean by "test the example ... regarding zero
>>>>>>>> power factor". If you are going to change some of the existing 
>>>>>>>> dispatchable
>>>>>>>> loads to have a zero power factor, then the existing market structure 
>>>>>>>> for
>>>>>>>> the example, which includes only $/MW bids for active power, will not 
>>>>>>>> be
>>>>>>>> applicable. So you need to decide how you want to handle these 
>>>>>>>> reactive-only
>>>>>>>> loads. I suppose you'll need to specify reactive power bids for them.
>>>>>>>>
>>>>>>>> On your second question, the offers and bids are used to construct a
>>>>>>>> gencost matrix with negative costs for the negative generators that
>>>>>>>> represent dispatchable loads. The objective function is then to 
>>>>>>>> minimize
>>>>>>>> this "cost" of generation, which is computed in opf_costfcn.m. You
>>>>>>>> are correct that this is equivalent to maximizing social welfare.
>>>>>>>>
>>>>>>>> --
>>>>>>>>  Ray Zimmerman
>>>>>>>> Senior Research Associate
>>>>>>>> 211 Warren Hall, Cornell University, Ithaca, NY 14853
>>>>>>>> phone: <%28607%29%20255-9645> 
>>>>>>>> <%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645>(607)
>>>>>>>> 255-9645
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> On Mar 8, 2011, at 5:04 PM, Carlos Gonzalez Almeida wrote:
>>>>>>>>
>>>>>>>> Dear Dr. Zimmerman
>>>>>>>>
>>>>>>>> -Could you please test the example provided in the manual
>>>>>>>> (t_auction_case) regarding zero power factor. What changes should be 
>>>>>>>> carried
>>>>>>>> out?
>>>>>>>>
>>>>>>>> -Moreover, as you know, the objective function obtained in the
>>>>>>>> runmarket is Social welfare. Could you please address me the file that 
>>>>>>>> you
>>>>>>>> calculated objective function because I couldn't find it.  I want to 
>>>>>>>> know in
>>>>>>>> which file (the m file) you have calculated that?
>>>>>>>>
>>>>>>>> Best Regards
>>>>>>>>
>>>>>>>> Carlos
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> On Tue, Mar 8, 2011 at 22:34, Ray Zimmerman <[email protected]>wrote:
>>>>>>>>
>>>>>>>>> I'm not really sure without seeing the details of your example. I'm
>>>>>>>>> not sure I've ever tested the runmarket code with pure reactive
>>>>>>>>> power loads. It would require reactive power bids for those loads, 
>>>>>>>>> but I'll
>>>>>>>>> need the details to be able to help you further.
>>>>>>>>>
>>>>>>>>>  --
>>>>>>>>> Ray Zimmerman
>>>>>>>>> Senior Research Associate
>>>>>>>>> 211 Warren Hall, Cornell University, Ithaca, NY 14853
>>>>>>>>> phone: <%28607%29%20255-9645> 
>>>>>>>>> <%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645><%28607%29%20255-9645>(607)
>>>>>>>>> 255-9645
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> On Mar 7, 2011, at 10:42 AM, Carlos Gonzalez Almeida wrote:
>>>>>>>>>
>>>>>>>>> Hi
>>>>>>>>>
>>>>>>>>> I am new in MATPOWER abd I want to have zero power factor for
>>>>>>>>> example in example case of manual in runmarket, but several error are
>>>>>>>>> occured. please tell me why
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Best Wishes
>>>>>>>>>
>>>>>>>>> C. Gonzalez Almeida
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> Best Wishes
>>>>>>>>
>>>>>>>> C. Gonzalez Almeida
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>> Best Wishes
>>>>>
>>>>> C. Gonzalez Almeida
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>>
>>>
>>
>>
>>
>
>
> Best Wishes
>
> C. Gonzalez Almeida
>

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