If you used the A, l and u fields of the MATPOWER case struct (mpc) to specify
the constraints, then the multipliers are in …
results.lin.mu.l.usr
results.lin.mu.u.usr
Note that these will be relative to power in p.u. not in MW, so you’ll have to
divide by baseMVA to get prices in $/MW.
--
Ray Zimmerman
Senior Research Associate
B30 Warren Hall, Cornell University, Ithaca, NY 14853 USA
phone: (607) 255-9645
On Oct 16, 2014, at 12:52 PM, vids <vidaj...@gmail.com> wrote:
> Hi Dr Zimmerman,
> How do i access the multipliers for the additional constraint that I
> added? thank you
>
> On Tue, Sep 2, 2014 at 10:26 PM, Ray Zimmerman <r...@cornell.edu> wrote:
>> Can you accomplish what you want simply by including the base dispatch in
>> the PD column of the bus matrix (where injections would appears as negative
>> loads)?
>>
>> --
>> Ray Zimmerman
>> Senior Research Associate
>> B30 Warren Hall, Cornell University, Ithaca, NY 14853 USA
>> phone: (607) 255-9645
>>
>> On Aug 28, 2014, at 10:10 PM, vids <vidaj...@gmail.com> wrote:
>>
>> Thank you very much, Dr. Shri. Yes i think your suggestion about
>> making the delta Pg as the control variables is a great idea. However
>> I am new to Matpower. Can you help me/ direct me to some examples on
>> how i can accomplish this? Thank you very much...
>>
>> On Thu, Aug 28, 2014 at 12:23 AM, Abhyankar, Shrirang G.
>> <abhy...@mcs.anl.gov> wrote:
>>
>> Vids,
>> Implementing your reformulated OPF equations, written in complementarity
>> form, is non-trivial in MATPOWER as it will require modifying the
>> variable/equation sizes and muddling with the OPF data structures. Note
>> that you'll also need additional equations, perhaps expressed in
>> semi-smooth form, relating your upward/downward balancing service to
>> generator power deviation. You will have to spend some time to understand
>> the OPF data structures and how they are used in the various OPF routines.
>>
>> One other possible way (that I think will work) is by using the real power
>> generator deviation \Delta{Pg} as the control variable instead of Pg (see
>> the attached equations). This will keep the sizes of the
>> variables/equations for the reformulated OPF same as the original one.
>> However, you will have to modify the cost function, gradient, Hessian, and
>> the generator real power limits accordingly.
>>
>> Shri
>>
>> -----Original Message-----
>> From: vids <vidaj...@gmail.com>
>> Reply-To: MATPOWER discussion forum <matpowe...@list.cornell.edu>
>> Date: Wed, 27 Aug 2014 16:18:14 +0800
>> To: <matpower-l@cornell.edu>
>> Subject: Modifying the Power Balance Equations
>>
>> Hi Dr Zimmerman and Matpower Community,
>>
>> I am trying implement an OPF where the real power dispatch is
>> pre-determined (as in the case of an energy market where the Q
>> schedules are managed separately by the transmission operator).
>>
>> Is it possible to implement it in Matpower? My idea is to add "slack"
>> variables in the nodal energy equations
>>
>> Pgi - ΔPgi + Pb1i - Pb2i - Pdi = ΣViVjYij(cos(θij + δi -δj)
>>
>> Pgi - fixed/predetermined real power generated at node i
>> ΔPgi - real power 're-scheduling' due to the reactive power dispatch
>> Pb1i - upward balancing service at node i
>> Pb2i - downward balancing service at node i
>>
>> Pb1i and Pb2 will have non-zero values when ΔPgi is nonzero, prompting
>> other generators to compensate the real power 're-scheduling' when
>> needed.
>>
>> This is the formulation in the dissertation of Dr. El-Samahy, and I
>> am wondering if this can be implemented in matpower.
>>
>> Any ideas would greatly be appreciated. Thank you very much.
>>
>> --
>> 2 Cor 12:9
>> Each time he said, "My grace is all you need. My power works best in
>> weakness." So now I am glad to boast about my weakness, so that the
>> power of Christ can work through me.
>>
>>
>>
>>
>>
>>
>> --
>> 2 Cor 12:9
>> Each time he said, "My grace is all you need. My power works best in
>> weakness." So now I am glad to boast about my weakness, so that the
>> power of Christ can work through me.
>>
>>
>>
>
>
>
> --
> 2 Cor 12:9
> Each time he said, "My grace is all you need. My power works best in
> weakness." So now I am glad to boast about my weakness, so that the
> power of Christ can work through me.
>
>
