Thank you very much for your help, Dr Ray. I added a small linear cost, and the difference became very small. I have yet to try adding small identical quadratic cost. I misunderstood the previous post on how to implement a loss minimization objective function, regardless of the generator cost. I should have added identical small cost functions instead of identical zero cost functions. Thanks again.
On Tue, Sep 2, 2014 at 10:39 PM, Ray Zimmerman <[email protected]> wrote: > Both cases have a all generator cost functions equal to zero, so all > feasible power flow solutions are optimal. That is, there isn’t even a > unique *local* optima, let alone a global optima. Under such circumstances, > numerical optimization routines such as those used by MATPOWER, should not > be expected to produce anything unique or consistent. Adding a small > quadratic real power cost for each generator does result in consistent > solutions for the two cases (to numerical accuracy of the algorithms). > > -- > Ray Zimmerman > Senior Research Associate > B30 Warren Hall, Cornell University, Ithaca, NY 14853 USA > phone: (607) 255-9645 > > On Sep 1, 2014, at 10:42 AM, vids <[email protected]> wrote: > > Hi Matpower Community, > > I was testing the application of reactive capability curve limits. I > defined a generator operating region by using the points described in > section 6.4.3 in the manual. > I first performed the OPF without including the parameters, and then > compared it with the results when the PQ curve limitation was > included. I was expecting the same results because the operating point > is very well within the operating region defined by the limits. But > the results were two slightly different operating points. Is this > really how Matpower behaves? I am attaching the two case files, in > case. Thank you very much! > > Vids > <capabilitytests_1.m><capabilitytests_2.m> > > -- 2 Cor 12:9 Each time he said, "My grace is all you need. My power works best in weakness." So now I am glad to boast about my weakness, so that the power of Christ can work through me.
