See FAQ #1 <http://www.pserc.cornell.edu/matpower/#lossminimization>.

   Ray


> On Nov 10, 2016, at 10:15 PM, Angel Pastor <[email protected]> wrote:
> 
> Thankyou for the help, mister Ray, i did what you told me and the OPF 
> converged, i put generators in every bus and had to modify my voltage 
> constraints from Vmax=1.05 and Vmin=0.95 to Vmax=1.1 and Vmin=0.9, and also 
> some branch flow constraints, but i think i can solve that by checking the 
> loads...
> 
> 
> Now, i wanna modify the OPF's objective function to minimize the power losses 
> in the branches, and the reactive power compensation (the reactive power 
> injected by the generators that i added), ¿how can i access the objective 
> function to make the modifications?
> 
> 
> 
> De: [email protected] 
> <mailto:[email protected]> 
> <[email protected] 
> <mailto:[email protected]>> en nombre de Ray 
> Zimmerman <[email protected] <mailto:[email protected]>>
> Enviado: martes, 08 de noviembre de 2016 02:43 p.m.
> Para: MATPOWER discussion forum
> Asunto: Re: Optimal reactive compensation in MATPOWER
>  
> If you have a power flow solution, you could relax the generator, voltage and 
> branch flow limits to include the power flow solution. Then gradually begin 
> to tighten the constraints by moving the limits gradually toward their 
> original values and resolving the OPF. This way you may be able to discover 
> which constraints are in conflict with one another.
> 
>     Ray
> 
> 
>> On Nov 8, 2016, at 11:05 AM, Angel Pastor <[email protected] 
>> <mailto:[email protected]>> wrote:
>> 
>> And ¿is there a way to "make" the OPF converge?... Which would be the main 
>> reasons why an OPF does not converge? 
>> 
>> 
>> De: [email protected] 
>> <mailto:[email protected]> 
>> <[email protected] 
>> <mailto:[email protected]>> en nombre de Ray 
>> Zimmerman <[email protected] <mailto:[email protected]>>
>> Enviado: martes, 08 de noviembre de 2016 11:45 a.m.
>> Para: MATPOWER discussion forum
>> Asunto: Re: Optimal reactive compensation in MATPOWER
>>  
>> I’m afraid I cannot speculate on the reasons for non-convergence of the OPF 
>> in your case. There are numerous ways in which an OPF problem can end up 
>> with an empty feasible region.
>> 
>>    Ray
>> 
>> 
>>> On Nov 8, 2016, at 12:07 AM, Angel Pastor <[email protected] 
>>> <mailto:[email protected]>> wrote:
>>> 
>>> Thank's for your answer mister Zimmerman, i tried with some of the cases in 
>>> the Matpower files like the case30 and case14 and it worked.
>>> 
>>> 
>>> But in the system i'm working the OPF does not converge and it says it 
>>> numerically fails, when i run the normal power flow it converges but it 
>>> doesn't satisfy neither the voltage or the generation constraints, ¿that 
>>> could be the reasson why the OPF does not converge?
>>> 
>>> 
>>> I was trying to apply an optimal reactive compensation to solve that 
>>> problem and get the OPF satisfying all the constraints.
>>> 
>>> 
>>> 
>>> De: [email protected] 
>>> <mailto:[email protected]> 
>>> <[email protected] 
>>> <mailto:[email protected]>> en nombre de Ray 
>>> Zimmerman <[email protected] <mailto:[email protected]>>
>>> Enviado: lunes, 07 de noviembre de 2016 11:06 a.m.
>>> Para: MATPOWER discussion forum
>>> Asunto: Re: Optimal reactive compensation in MATPOWER
>>>  
>>> You could add a generator at each bus and then use an OPF to solve for the 
>>> power flows, with the real power dispatches constrained to their initial 
>>> values.
>>> 
>>>     Ray
>>> 
>>> 
>>>> On Nov 6, 2016, at 9:40 AM, Angel Pastor <[email protected] 
>>>> <mailto:[email protected]>> wrote:
>>>> 
>>>> Dear MATPOWER community.
>>>> 
>>>> Hi to everyone, i'm trying to implement reactive power compensation in a 
>>>> power system, my goal is to make voltage in all buses have values within 
>>>> the constraints, but i don't know neither the ubication for the 
>>>> compensation or the MVAR's that  would give me the optimal solution and 
>>>> satisfy all the constraints. So i was wondering if there is a way for 
>>>> matpower to get me that information.
>>>> 
>>>> My system consist in 14 buses, 5 PV (one generator per bus) and 9 PQ. I 
>>>> was thinking in modeling the compensators as reactive power generators 
>>>> with no Pg, as in a OPF the reactive power generated Qg is an optimization 
>>>> variable, but i only have that variable in the PV buses, and i need to be 
>>>> able to compensate in any bus to have the optimal solution.
>>>> 
>>>> I could make all the buses PV to put generator in all the buses, but then 
>>>> the voltage would be attached to de Vg values from the gen_matrix.
>>>> 
>>>> Other idea i had was to add a new variable with the add_userfcn. function 
>>>> and change the OPF formulation with
>>>> 
>>>> function om = userfcn_reserves_formulation(om, args)
>>>> 
>>>> But i think that variable would still be limitated to to the PV buses and 
>>>> would only add a reserve to the current generators.
>>>> 
>>>> If you could help me with this, i would really appreciate it.
>>>> 
>>>> Hoping to get response. Thanks in advance.
>>>> 
>>>> Angel Araque, Electrical Engineering student in University of Los Andes. 
>>>> Venezuela

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