Maybe the generation costs you are using for the opf are causing problems. Try to check that!.
Regards, Santiago 2011/6/28 Fanjun Meng <[email protected]> > Thank you very much for your suggestion! > Actually I did check the simple power flow result with constraints, the > voltages, line flows, generations are all satisfied. That's why I'm confused > with this problem. Is it possible that the line impedences and system > topology may cause matrix sigularity during OPF calculation iteration and > fail to converge? > > Thanks a lot! > > *Fanjun Meng > * > > > > > On Tue, Jun 28, 2011 at 10:13 AM, Santiago Torres <[email protected] > > wrote: > >> The simple power flow has not constraints, so maybe with the settings you >> are using the power flow converges and has solution, however when you use >> the opf, some constraints can cause it does not converge. Check if the IEEE >> 123 node reported solution when using the simple power flow is complying the >> constraints (ie voltages, power generation, power flows). >> >> I hope this can help. >> >> Santiago Torres >> >> 2011/6/28 Fanjun Meng <[email protected]> >> >>> Hello, >>> >>> I've been working on IEEE 123 nodes system and created a model for >>> MatPower power flow. This model is basically a radial distribution system >>> with a single generation at substation and works fine when I can use >>> runpf(), and it returns similar result as shown IEEE 123 node system report. >>> However, when I use the same model for runopf(), it shows >>> >>> >>> Numerically Failed >>> Did not converge in 4 iterations. >>> Did not converge (0.10 seconds) >>> >>> The total generation is very different from total demand, and bus >>> voltages are at strange values (e.g. 1.836p.u. at reference bus). Also, >>> generation cost Lambda are extremely high (e.g. 17528752586.76 $/MWh @ bus >>> 6). I have tried to add multiple DGs at different locations and change the >>> system to a ring type system, but it didn't work out. Does anyone have any >>> suggestions or experiences to this problem? Your help is highly appreciated! >>> >>> Have a good day!* >>> >>> Fanjun Meng >>> * >>> >>> >> >> >> -- >> Dr.-Ing. Santiago Torres >> IEEE Senior Member >> >> Post-Doctoral Fellow >> School of Electrical and Computer Engineering >> University of Campinas, Campinas, SP, Brazil >> >> http://www.dsee.fee.unicamp.br/ >> >> Albert Einstein, 400 >> 13083-852, Campinas, SP, Brazil >> > > -- Dr.-Ing. Santiago Torres IEEE Senior Member Post-Doctoral Fellow School of Electrical and Computer Engineering University of Campinas, Campinas, SP, Brazil http://www.dsee.fee.unicamp.br/ Albert Einstein, 400 13083-852, Campinas, SP, Brazil
