Hi Enrico,
I had a quick look at your case. Firstly, the results you get when running an
DC PF on your case are normal. The active power is fixed at all Load and
Generator buses, and therefore only the slack bus can add/remove active power
to the system in order to find a solution. Given that all your generators begin
with 0 MW of active power production, you find that all power must be produced
at your slack bus.
I tried running an ACOPF on your model, using:
mpopt = mpoption('verbose', 3, 'out.force', 1,'pf.nr.max_it',10);
runopf(mpc,mpopt);
This doesn’t converge, but the output suggests a few issues with your model. If
you look at the branch constraints, you’ll find that some of your branches with
the greatest capacity are only being utilized <5%. Whilst a few low capacity
branches (150, 290, 369, 370) have absurdly large flows. This implies to me
that you either have some branches connected to the wrong buses, or have some
errors in the electrical parameters of your lines.
Note that it is possible to get an ACOPF to converge on your case if you apply
the following modifications/simplifications, which supports my argument that
there is probably a few errors in your branch data:
mpc.branch(:,RATE_A) = 0;
mpc.branch(:,BR_R) = 0.1*mpc.branch(:,BR_R);
mpc.branch(:,BR_X) = 0.001*mpc.branch(:,BR_X);
I hope this helps you debug your case, and good luck with your thesis.
Kind regards,
Samuel Perkin
From: [email protected]
[mailto:[email protected]] On Behalf Of Enrico
Vaccariello
Sent: 20. febrúar 2017 02:25
To: [email protected]
Subject: Sequential OPF: Non-convergence of both OPF and PF
Dear All MATPOWER developers and users,
I really hope some of you can give me some advice.
I am working on sequential OPF simulations (not using MOST, but simply running
MATPOWER's runopf in a loop and manually updating some values the MATPOWER case
at each time-step t) to be performed on a case(s) that I have been working a
lot to prepare.
Anyway, unfortunately, now that the time of running the simulation has finally
come, I have some serious convergence issues.
With the 285-bus case structs that I have built, the OPF simulation running
with the default MIPS does not converge.
The case structs differ one from another for some parameters as a function of t
(time-step of the loop). Anyway, whatever the t I set, the OPF won't converge
in any case, so there must be some structural issue of my cases I guess.
I'll attach the case of t=1 to this mail for who wishes to have a look.
Making some tests, I have found out that the PF simulation does not converge
either. Among the (non-converged) results of the PF it seems that the slack bus
is the only trying to generate active power (a lot of), whereas all the others
do not dispatch, i.e. results.gen(:,PG) is zero for all the generators of the
PV buses.
What is more, the same generators dispatch very high quantities of reactive
power, much beyond their lower and upper limits.
If someone could help I would be very grateful... Last days for my thesis, very
hard times!
Thank you and best regards.
Enrico
