But the voltage solution to the OPF problem should satisfy all of the power flow equations. Unless I’m missing something, running …

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runpf(runopf(mpc)) … should always result in immediate convergence of the power flow, without iterating, assuming the OPF solved successfully. Ray > On Sep 9, 2016, at 3:30 AM, Jose Luis Marín <mari...@aia.es> wrote: > > > Just a guess: OPF observes limits QMIN and QMAX on generators, while a > powerflow (with the standard option pf.enforce_q_lims=0) does not. Although > not typical, it is certainly possible for a powerflow case to be infeasible > when solving without generator MVAR limits, and solvable when enforcing them. > > Take a look at your OPF solution and check if there are many generators > pegged at their Q limits or not. > > -- > Jose L. Marin > Grupo AIA > > > > 2016-09-08 14:45 GMT+02:00 Gamze Dogan <gamgam...@hotmail.com > <mailto:gamgam...@hotmail.com>>: > 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 >> <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 >>> >>> >>> >