You can see how the OPF model is constructed in …
opf_setup()
The generator costs (piecewise linear and linear or quadratic) are handled via
add_quad_cost(). Then there are two other functions that are used to handle any
higher-order polynomial generator costs or legacy user-defined costs ...
opf_gen_cost_fcn()
opf_legacy_user_cost_fcn()
The nodal mismatch equality constraints are implemented by …
opf_power_balance_fcn()
opf_power_balance_hess()
The branch flow inequality constraints are implemented by …
opf_branch_flow_fcn()
opf_branch_flow_hess()
Btw, this is all in MATPOWER 7.0b1.
Hope this helps,
Ray
> On Apr 11, 2019, at 12:45 PM, Morteza Dabbaghjamanesh <[email protected]> wrote:
>
> Hi,
> Is there any way to change the default constraints and objective cost
> function of OPF (even if it requires to change the source code of manpower)?
> I am very much inquisitive to know where should I start if I really need to
> change the default constraints and objective cost function?
>
> Sincerely,
>
> From: [email protected]
> <mailto:[email protected]>
> <[email protected]
> <mailto:[email protected]>> on behalf of Ray
> Zimmerman <[email protected] <mailto:[email protected]>>
> Sent: Tuesday, April 9, 2019 4:32:34 PM
> To: MATPOWER discussion forum
> Subject: Re: Using conventional parameters as variables in opf
>
> Yes.
>
>> On Apr 9, 2019, at 4:30 PM, Morteza Dabbaghjamanesh <[email protected]
>> <mailto:[email protected]>> wrote:
>>
>> Thank you very much for your reply, so if I set pf.enforce_q_lims equal to
>> 1, it will do the PV-PQ switching?
>>
>> Sincerely,
>>
>>
>> From: [email protected]
>> <mailto:[email protected]>
>> <[email protected]
>> <mailto:[email protected]>> on behalf of Ray
>> Zimmerman <[email protected] <mailto:[email protected]>>
>> Sent: Tuesday, April 9, 2019 3:23:49 PM
>> To: MATPOWER discussion forum
>> Subject: Re: Using conventional parameters as variables in opf
>>
>> I could be wrong, but I would be very, very surprised if the near singular
>> matrix issue is related to modeling the shunt susceptances as generators.
>> The only other idea I have is to call the OPF iteratively as a subroutine
>> with fixed shunt susceptances that you update according to your own
>> optimization at each iteration.
>>
>> Regarding PV, PQ switching during the power flow, have a look at the
>> pf.enforce_q_lims option (help mpoption or Table 4-2 or Table C-2 in the
>> manual
>> <https://nam04.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.pserc.cornell.edu%2Fmatpower%2Fdocs%2FMATPOWER-manual-7.0b1.pdf&data=02%7C01%7Cmdabba1%40lsu.edu%7C9a697a24a5d9440d5ec308d6bd32ec8e%7C2d4dad3f50ae47d983a09ae2b1f466f8%7C0%7C0%7C636904423748376878&sdata=ZFj4Zepgx6rPQLHQTuq6uFZ8NeGoD8cZIqpHI4QPhEc%3D&reserved=0>).
>>
>> Ray
>>
>>
>>> On Apr 9, 2019, at 11:50 AM, Morteza Dabbaghjamanesh <[email protected]
>>> <mailto:[email protected]>> wrote:
>>>
>>> Thanks for your reply. I have been able to fix the problem but can you
>>> suggest any alternative way of converting the OPF parameters as variables
>>> because I guess adding the shunt susceptances as generators is taking the
>>> matrix close to singularity as I am getting some warning.
>>>
>>> One more question, does matpower do PV , PQ switching while solving the
>>> Power Flow?
>>>
>>> Sincerely,
>>>
>>> From: [email protected]
>>> <mailto:[email protected]>
>>> <[email protected]
>>> <mailto:[email protected]>> on behalf of Ray
>>> Zimmerman <[email protected] <mailto:[email protected]>>
>>> Sent: Tuesday, April 9, 2019 9:00:08 AM
>>> To: MATPOWER discussion forum
>>> Subject: Re: Using conventional parameters as variables in opf
>>>
>>> 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
>>> <https://nam04.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.pserc.cornell.edu%2Fmatpower%2Fdocs%2FMATPOWER-manual-7.0b1.pdf&data=02%7C01%7Cmdabba1%40lsu.edu%7C9a697a24a5d9440d5ec308d6bd32ec8e%7C2d4dad3f50ae47d983a09ae2b1f466f8%7C0%7C0%7C636904423748386887&sdata=mYWOeN5C2B%2F2cbU%2FJDENnvirep8GWW1lRakeM8pAUGI%3D&reserved=0>
>>> 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]
>>>> <mailto:[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://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Faka.ms%2Fo0ukef&data=02%7C01%7Cmdabba1%40lsu.edu%7C9a697a24a5d9440d5ec308d6bd32ec8e%7C2d4dad3f50ae47d983a09ae2b1f466f8%7C0%7C0%7C636904423748386887&sdata=IKuJK6SA7QJTPD2Pi8tAuyjW85NQ4i%2FWpEX%2FMwV9Yk8%3D&reserved=0>
>>>>
>>>> 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
