Dear Dr. Zimmerman, Thank you so much for your corrections and notes. I agree with all of them, and I do not think you are missing something.
Best regards, Haneen Aburub On Wed, Nov 9, 2016 at 2:17 PM, Ray Zimmerman <[email protected]> wrote: > I assume this data is from the Baran, Wu paper [1]. A couple of comments > ... > > 1. Setting RATE_A column to zero is actually correct for a case with no > branch flow limits (see footnote 14 at the bottom of p. 49 in the latest > User’s > Manual > <http://www.pserc.cornell.edu/matpower/docs/MATPOWER-manual-6.0b2.pdf>). > > 2. In the case file you sent, all of the tie lines are in-service, > operating as a meshed system, rather than the base radial configuration, > and the branch impedance parameters for 5 of the branches (every other > branch starting with the first) do not match exactly what’s shown in the > paper. > > 3. I’ve attached attached a version of the case that I believe matches the > data from the paper exactly. > > 4. Unless I’m missing something, the data given in the paper and the base > case solution given in the paper are not consistent. For one thing, the > voltages do not match, but even more glaring is the fact that the total > load is 3715 kW, but they claim the total substation load is 5085.26 kW and > that the losses are about 8%. Am I missing something? > > Ray > > > [1] M. E. Baran and F. F. Wu, "Network reconfiguration in distribution > systems for loss reduction and load balancing," in IEEE Transactions on > Power Delivery, vol. 4, no. 2, pp. 1401-1407, Apr 1989. doi: > 10.1109/61.25627 URL: http://doi.org/10.1109/61.25627 > > > > > On Nov 8, 2016, at 3:07 PM, Haneen Aburub . <[email protected]> wrote: > > Thank you so much for your help. It worked now after doing the > modifications that you suggested. > > On Tue, Nov 8, 2016 at 1:51 PM, André Carvalho Silva < > [email protected]> wrote: > >> Hi there Haneen, >> >> By thaking a quick look at your matpower case, it seems fairly obvious >> that the branch flow limits (rate A in MVA) are missing (they cannot >> be equal to zero). >> >> Also, you should put some P and Q limits in your generator (Qmin, >> Qmax, Pmin and Pmax generator fields). >> >> >> Best regards, >> André Silva >> >> >> >> Citando "Haneen Aburub ." <[email protected]>: >> >> > Dear Matpowers, >> > >> > I tried to run a simple AC OPF for IEEE 33-bus (12.66 kV) distribution >> > system using PDIPM solver, but it failed. It gave me the following >> error: >> > >> > IPM Numerically Failed: unable to solve Ax=b. >> > >> > My system has only a generator at bus 1 (ref bus) and a linear cost >> > function for that generator. >> > >> > The AC PF using NR converged fine, but I do not know why the AC OPF did >> not >> > converge? >> > >> > I tried to relax the voltage limits (0.9-1.1) and using the AC PF >> solution >> > as a start for AC OPF. But these options did not work too. >> > >> > Could you please help. I attached my case.m file >> > >> > Best regards, >> > >> > Haneen >> > >> >> >> >> ---------------------------------------------------------------- >> This message was sent using IMP, the Internet Messaging Program. >> >> >> > > >
