Thank you all for your suggestions. I will check all of them ASAP and write back if still have a problem.
среда, 21 января 2015 г. пользователь Ray Zimmerman написал: > Also, for the OPF problems you may want to try a different solver if you > have any available. The default MIPS solver is not always the most robust. > Another thing to look for is branches with extremely small reactances, > which can cause numerical problems. If the reactance is small enough, it > makes sense to just merge the buses and eliminate the branch. > > Ray > > > On Jan 20, 2015, at 5:27 PM, Abhyankar, Shrirang G. <[email protected] > <javascript:_e(%7B%7D,'cvml','[email protected]');>> wrote: > > http://www.pserc.cornell.edu//matpower/#pfconvergence > > On Jan 20, 2015, at 2:47 PM, "Jorge Fernando Gutiérrez Gómez" < > [email protected] <javascript:_e(%7B%7D,'cvml','[email protected]');>> > wrote: > > Dear Mr. Uzbekov, I think that your case could be an ill-conditioned or > an unsolvable one. In power system problems that means that: > > > * Its loading level is close its maximum loading point or beyond it (in > this case it is unsolvable). > > * Maybe you are using a poor initial guess. That situation could lead a > standard solver (as Newton-Raphson) to a trajectory that diverges. This > occurs although actually there is a feasible operating point. > > > Best regards, > > > > > > > On Tue, Jan 20, 2015 at 2:48 PM, Artur Uzbekov < > [email protected] > <javascript:_e(%7B%7D,'cvml','[email protected]');>> wrote: > >> Dear Mr. Zimmerman, >> >> Or anyone who can help me. >> I am trying to run a model of a big grid in Matpower. >> It has 130 loads, 329 generators and 286 branches. >> I obtain an optimal solution for DC Power Flow problem which is most >> probably correct (it corresponds to the real data). >> But For AC Power Flow and both DC and AC OPF problems, I get the >> following message: >> Warning: *Matrix is close to singular or badly scaled. Results may be* >> *inaccurate. *And the success flag is 0. >> >> I have checked that the are no islands in the network. >> In some forums people write that it could happen due to the bad modelling >> or too heavy loads. >> But for me this explanation is not clear. Can you please comment on that >> or suggest any other explanation. >> >> Looking forward to hear from you! >> Arthur >> > > > > -- > Jorge Fernando > > >
