Your logic sounds correct. You might also just try putting a large positive cost on the slack bus gen and zero costs on all of the DGs. It should be equivalent. It could be that there is some tradeoff between maximizing DG and minimizing losses and the value used for DG cost affects this tradeoff.
-- Ray Zimmerman Senior Research Associate B30 Warren Hall, Cornell University, Ithaca, NY 14853 phone: (607) 255-9645 On Jun 13, 2013, at 7:38 AM, Dionisis Stamatiadis <[email protected]> wrote: > Hi, > I am using MatPower during my MSc thesis in which I study the behaviour of a > storage system connected to a distribution network with distributed > generators (DGs). My objective is to maximise the DG export subject to the > grid's constraints (voltages, line limits) - objective function: max Pdg. I > though that putting the costs of the main grid's generator (slack bus) equal > to zero, and the DGs' costs a negative value I would get the maximum DG > output. However, it seems that this is not the case since I get a different > DG export for different negative costs. If I was right, then the DG export > (maximum achieved subject to system constraints) should be the same for every > negative cost. > > Do you think that my thinking is wrong? What would you suggest me to do in > order to maximise the DG export. I read section 5.3 but I think that I do not > have to add more variables and costs, since I can model DG units as plain > generators. > > Thank you in advance, > Dionisis >
