If it is not converging, it is likely (though not absolutely certain) that the
problem is infeasible. I suggest that you try turning on soft limits to see if
the OPF will converge with a few constraint violations. That can show you which
are the conflicting constraints. MATPOWER 7.0b1 has a much improved soft-limit
capability, so definitely get 7.0b1 if you don’t already have it. See Section
7.6.4 in the MATPOWER User’s Manual
<http://www.pserc.cornell.edu/matpower/docs/MATPOWER-manual-7.0b1.pdf> for more
details on OPF soft limits.
Then do …
mpc = loadcase('<your case>');
mpc = toggle_softlims(mpc, 'on');
r = runopf(mpc);
Oh, and by the way, PQ vs PV makes no difference for the OPF, only for the
power flow.
Hope this helps,
Ray
> On Apr 1, 2019, at 11:51 PM, Morteza Dabbaghjamanesh <[email protected]> wrote:
>
> Hi,
>
> I have already set the Vmax and Vmin in mpc.bus section to Vg but the
> condition gets worse, the OPF is not converging now. Previously, though I
> have seen convergence but I have voltage violation almost in every buses of
> my system and this is also happening now. Do you have any idea why this is
> happening or how to get rid of this issue? Does switching from PQ to PV bus
> seems reasonable to you?
>
> If you can suggest some alternative way even it is difficult, it will be of
> great help to me.
>
> Regards,
>
>
> Get Outlook for iOS <https://aka.ms/o0ukef>
>
> From: [email protected]
> <mailto:[email protected]> on behalf of Ray
> Zimmerman <[email protected] <mailto:[email protected]>>
> Sent: Monday, April 1, 2019 5:25 PM
> To: MATPOWER discussion forum
> Subject: Re: Using conventional parameters as variables in opf
>
> There is not an easy way to convert a parameter (like shunt susceptance) to
> an OPF variable. The approach you are already taking is what I would suggest.
> It sounds like you may not have set VMIN and VMAX to the desired voltage
> (VG).
>
> On your second question, yes, the gencost matrix is always assumed to be
> ordered exactly the same as the gen matrix. That is, row i in one corresponds
> to row i in the other.
>
> Ray
>
>
>> On Apr 1, 2019, at 11:03 AM, Morteza Dabbaghjamanesh <[email protected]
>> <mailto:[email protected]>> wrote:
>>
>> Hi,
>>
>> I was wondering whether there is any way of converting a parameter into a
>> variable in OPF. Say for example, if I want to convert the shunt susceptance
>> which is usually passed as a parameter to the OPF , to a variable, what is
>> the easiest way of doing it.
>>
>>
>> Currently, I am considering shunts as reactive generators which can only
>> produce reactive power and no real power, to implement that, I have appended
>> new rows equal to the number of shunt buses in the generator section of mpc
>> data. Then I set the 'Pg','Pmax' and 'Pmin' to zero. I collected the voltage
>> from the bus data section and passed it to the 'Vg' of the new added rows. I
>> have also added some rows in the generator cost section (appended at the
>> last of the existing cost of the generators). I have set the 'Qmax' and
>> 'Qmin' from my maximum and minimum shunt susceptance. I have also changed
>> the bus types to 'PV' from 'PQ' mode (in applicable cases). Though I am
>> having an OPF solution but looking at the results there are voltage limit
>> violation in almost every buses. Can you please suggest what could be the
>> solution of this problem?
>>
>>
>> Another issue is, if I add any new generator to the power flow data, then
>> should I add the generator cost information at the end of the existing
>> generator cost or should I insert them as per the index of the generators.
>>
>> Best regards,
>> Morteza Dabbaghjamanesh
