I assume you are referring to consfmin.m. These derivatives, along
with the derivatives of the cost function in costfmin.m are used by
the fmincon solver during the solution process to update the search
direction. I assume fmincon also uses them to evaluate the 1st order
optimality conditions to determine if/when a solution has been found.
Ray
On May 9, 2007, at 4:48 AM, Sarina Adhikari wrote:
Dear Mr. Ray,
I have another very brief question. I have noticed in MATPOWER that
the derivatives of the constraints are calculated after the
calculation of the constraints. Does it represent the necessary
conditions as in an ordinary optimization process? How does it
affect the solution of OPF?
Hoping for your quick reply.
thank you.
On 5/8/07, Ray Zimmerman <[email protected]> wrote:
It is not possible to do this directly with the OPF. I'm not sure
if this will accomplish what you want, but first you could run the
OPF with relaxed voltage limits to find the real power dispatch.
Then use that real power dispatch and run a simple power flow with
the desired voltage setpoints and the ENFORCE_Q_LIMS option set to
true. Be aware that this could cause line limits to be violated.
--
Ray Zimmerman
Senior Research Associate
428-B Phillips Hall, Cornell University, Ithaca, NY 14853
phone: (607) 255-9645
On May 8, 2007, at 7:52 AM, Sarina Adhikari wrote:
Dear Sir,
I have been trying to fix the voltages of the generator buses
until the generator reactive power limits are reached. However,
when I do this, the OPF simply diverges. I have already relaxed
the line limits as well as voltage limits. The thing I am trying
to do is, fix the voltages of generator buses until the reactive
power limits are reached and if one of the generator hits the
reactive power limits, simply relax the voltage constraints of
that bus and so on. But I am really having problem with this.
Is this modification possible with matpower? If yes, what could be
the easiest way to do this?
I would be very much grateful if you could send me some
suggestions regarding this at the earliest as I have been stuck on
this point.
Looking forward to hearing from you soon.
sincerely
Sarina
