Dear Dr Zimmerman,Thanks a lot for your help.I ran a dc opf for case 24ieee
without considering any faults, for the whole year, in which the load in the
buses is the one determined from ieee reliability test system with annual
system peak 2850 MW and annual system min 965MW. For the hours that don't
converge, I checked the sum of the load for all the buses and the PMIN and
PMAX and I saw indeed what you said.For the times that the dcopf does not
converge the sum of pmin for the online generators is greater than the sum of
the load for that hour.So the dc opf does not converge for all the hours that
the load is lower that 1040 MW, which is the sum of Pmin for all the
generators.I am a bit confused!How I can solve that problem?Can I make the
assumption that the dcopf is a success for those cases?How can I control the
generators , in order to have some of them shut down for those cases?Thanks for
your time.Regards,Angelina
From: [email protected]
Subject: Re: negative generation on opf
Date: Mon, 22 Apr 2013 16:31:09 -0400
To: [email protected]
When the OPF does not converge, the result is often meaningless. Finding the
reason for unfeasibility can be a non-trivial task. Start by checking that
total fixed load lies between the sum of PMIN and the sum of PMAX for the
on-line generators. Try removing all of the line flow limits. Try a simple
power flow with what you think are reasonable voltage and real power set points
for the generators.
Once you find a feasible OPF solution you may be able to modify parameters
gradually toward the infeasible case to determine which constraints bind and
then conflict.
Hope this helps,
-- Ray ZimmermanSenior Research Associate419A Warren Hall, Cornell University,
Ithaca, NY 14853phone: (607) 255-9645
On Apr 22, 2013, at 2:19 PM, angelina sirri <[email protected]> wrote:
Dear Dr Zimmerman,
I am doing reliability study in case24_ieee_rts and I have put extra expensive
generators in load buses, in order to calculate the load curtailment.I did
acopf but for some hours opf did not converged and I saw that the Qmin and max
limits were violated.I couldn't find why, So I tried to do dcopf and now, it
does not converges again and I see that the extra generators that I have put,
some hours generate negative power of small value (like -0,0025).Have you got
any idea why is this happening or what should I check??
Regards,
Angelina
