Re: Problem with runcpf

[Abhyankar, Shrirang G.]

Please send me your case file (off-list) and I'll try to figure out the issue.

Shri

On Sep 8, 2016, at 7:47 AM, Gamze Dogan 
<gamgam...@hotmail.com<mailto:gamgam...@hotmail.com>> wrote:


Thank you for your answer,


I double check and my OPF does really converge. I also checked the buses and 
all my generators are PV and all my non-generators buses are PQ .
I have zero island. If anyone else has an idea why I do not converge even if my 
opf converge?

Thank you,


Regards,


Dogan


________________________________
De : 
bounce-120759695-68616...@list.cornell.edu<mailto:bounce-120759695-68616...@list.cornell.edu>
 
<bounce-120759695-68616...@list.cornell.edu<mailto:bounce-120759695-68616...@list.cornell.edu>>
 de la part de Abhyankar, Shrirang G. <abhy...@anl.gov<mailto:abhy...@anl.gov>>
Envoyé : mercredi 7 septembre 2016 14:16
À : MATPOWER discussion forum
Objet : Re: Problem with runcpf

Are you sure the OPF converged? If it did, then I guess you are not setting the 
bus types correctly or there is still some error in your system data. Note that 
the first step of a continuation power flow is running a load flow. So if the 
load flow does not converge then continuation power flow will not either.

On Sep 5, 2016, at 9:52 AM, Gamze Dogan 
<gamgam...@hotmail.com<mailto:gamgam...@hotmail.com>> wrote:


Thank you for your answer,


I actually had an island, but the problem remains. Now I am sure that there are 
no island.

The load flow does not converge.
I tried to launch a fast decoupled, but it does not converge.
The OPF converged and I used the results of Vm and Va as the initial guess to 
relauch my load flow, but it still does not converge.



I tried to check the system load using runcpf, but it does not converge, here 
is the message:


MATPOWER Version 5.1, 20-Mar-2015 -- AC Continuation Power Flow
step   1 : lambda = 26502.011, corrector did not converge in 10 iterations

>>>>>  Did NOT converge (0.20 seconds)  <<<<<


Do you have any suggestion on how I can make it converge?

Thank you,

Dogan


________________________________
De : 
bounce-120746902-68616...@list.cornell.edu<mailto:bounce-120746902-68616...@list.cornell.edu>
 
<bounce-120746902-68616...@list.cornell.edu<mailto:bounce-120746902-68616...@list.cornell.edu>>
 de la part de Abhyankar, Shrirang G. <abhy...@anl.gov<mailto:abhy...@anl.gov>>
Envoyé : vendredi 2 septembre 2016 13:42
À : MATPOWER discussion forum
Objet : Re: Problem with runcpf

I suspect you have isolated buses or islands that do not have a swing bus. Have 
you tried I-iv in MatPower faq on power flow divergence.

http://www.pserc.cornell.edu/matpower/#pfconvergence

Shri

On Sep 2, 2016, at 6:51 AM, Gamze Dogan 
<gamgam...@hotmail.com<mailto:gamgam...@hotmail.com>> wrote:


Dear all,

I have a problem when using runpf which does not converge. Therefore, I tried 
to check if the system load exceeded the steady-state loading limit (as 
mentionned on the website)

define_constants;
    mpcbase = loadcase('casefile');
    mpcbase.bus(:, PD) = 0;
    mpcbase.bus(:, QD) = 0;
    mpcbase.gen(:, PG) = 0;
    mpctarget = loadcase('casefile');
    results = runcpf(mpcbase, mpctarget);
    results.cpf.max_lam

But I have a problem using the function runcpf, it gives me the following error 
message:

Warning: Matrix is singular to working precision.
> In cpf_corrector at 124
  In runcpf at 257
step   1 : lambda =    NaN, corrector did not converge in 10 iterations
??? NaN's cannot be converted to logicals.

Error in ==> printpf at 175
    nzld = find((bus(:, PD) | bus(:, QD)) & bus(:, BUS_TYPE) ~= NONE);

Error in ==> runcpf at 392
printpf(results, 1, mpopt);

I do not understand what the problem is. Any suggestion is wellcome.

Thank you,

G. Dogan