You should not have to modify opf.violation if the problem is feasible. One thing you might try is to turn on OPF soft limits (see toggle_softlims). If it converges then you can see which limits had to be violated in order to solve the problem.
From what I can tell, it appears you are using the dispatchable loads correctly, except it looks like you have a typo in the line that assignes PMIN. Also, if you are constraining the voltage at the dispatchable load to the voltage setpoint using opf.use_vg, just make sure that you specify gen(disploadbus, VG) in p.u. Ray On Oct 15, 2020, at 12:46 PM, Davide Maglione <davide.maglion...@gmail.com<mailto:davide.maglion...@gmail.com>> wrote: Yes you are assuming correctly, i am trying to optimize the cost only to maximize the dispatchable load absorption. So i have currently : f(p) = c1 *p with p = Active power absorbed by the disp. Load. The Vm are constrained within the constraint values of the italian transmission network. I have not put constraints on Va. And the Pg and Qg (generators active and reactive power) are constrained within the production profiles i give them. I am having issues primarly with the V values. MIPS doesn’t converge because Vm and also the dispatchable P exceeds the constraints. The opf currently converges if i use “FMINCON” with an opf.violation set at 9*10^(-1) but i am noticing the results.var.val.Vm patterns being strange when i activate the dispatchable load mycase.gen(disploadbus,6)= V(disploadbus)/mycase.baseKVLL; mycase.gen(disploadbus,7)= mygen.baseMVA; mycase.gen(disploadbus,8) = 1 ; mycase.gen(disploadbus,9) = 0 ; mycase.gen(disploadbus i,10) = - 40 ; mycase.gencost(disploadbus,5) = c1; mycase.gencost(disploadbus ,6) = 0; I am simulating a storage device that activates when there are contingencies in the network, in order to avoid wind power curtailment. But little variation of the P injected results in too high variations of Vm during the opf simulations. Am i using the dispatchable load feature correctly? Thank you in advance for your kindness Ray, Best regards. Davide Da: Ray Daniel Zimmerman<mailto:r...@cornell.edu> Inviato: martedì 13 ottobre 2020 16:06 A: MATPOWER-L<mailto:matpowe...@list.cornell.edu> Oggetto: Re: Bus, Loads and Generators question Yes, the P absorbed by the dispatchable load appears as a negative generation, so the cost is evaluated using a negative quantity. I’m not sure what you mean by optimize Va, V, and P absorbed by the loads, but not other Pg and Qg. I assume you mean that they are all free variables, but the cost you are optimizing is simply to maximize the load served (and possibly some cost on voltage?). If so, then yes, you can set the other generator costs to zero. You could also simply set the costs to a positive constant that is small relative to the value of the load. That essentially says that there is no preference to use one generator over another. It’s likely that the problem as defined is infeasible, but just to be sure, it could be useful to attempt another solver, like IPOPT. Ray On Oct 12, 2020, at 1:13 PM, Davide Maglione <davide.maglion...@gmail.com<mailto:davide.maglion...@gmail.com>> wrote: Thank you for the time spent in answering my questions. I probably don’t need to add a new variable in my current scenario. I have done several tests with my network but i still have some issues. The P absorbed by the dispatchable load is treated as negative in the equation of the costs, am i right? If i want to optimize Va,Vm and P absorbed by the dispatchable loads , but not the other Pg and Qg, is it enough to put 0s in the respective gencost matrix’s rows? Unfortunatelly with the default options the program doesn’t converge, i have a numerical failure using MIPS. The P absorbed by the disp. Loads exceeds the constraints, and the Vm of the buses does it too, but i think that thanks to your help i am moving in the right direction. Thank you again, Davide Da: Ray Daniel Zimmerman<mailto:r...@cornell.edu> Inviato: venerdì 9 ottobre 2020 15:56 A: MATPOWER-L<mailto:matpowe...@list.cornell.edu> Oggetto: Re: Bus, Loads and Generators question The P absorbed by the dispatchable load is already an optimization variable, included in Pg, since dispatchable loads are modeled as negative generators. So you may not even need to add a variable. Furthermore, you can already impose costs on those variables via the gencost matrix. If you simply want to maximize the power absorbed by the dispatchable loads, you just need to make sure that you use a large enough negative cost (on the negative injection). You may find load2disp()<https://matpower.org/docs/ref/matpower7.0/lib/load2disp.html> to be helpful. If you do need a new variable, it is introduced through the A matrix in the user-defined linear constraints. You simply define linear constraints that include extra columns corresponding to the new variables. They are related to the existing variables through this constraint matrix whose existing columns correspond to Va, Vm, Pg, Qg, for the standard formulation. See equations (6.5) and (6.38), (6.39) in the manual. Ray On Oct 8, 2020, at 11:09 AM, Davide Maglione <davide.maglion...@gmail.com<mailto:davide.maglion...@gmail.com>> wrote: Hi Ray Thank you for your kind and fast response! I think your suggestion is right, i should lean toward the direct specification. I will try to be more clear about what i am trying to do. I have only one specific case, but i have to see what happens in different periods of time. I would like to initialize dispatchable loads in specific times inside my loop, and during those times i am trying to optimize (maximize) the surplus energy absorbed, coming from the generators. So what i have in mind, and i am sure it’s possible to do with your software, is to create a new variable (the P absorbed by the disp. Loads), add some constraints based on the maximum demand and voltage of the dispatchable Load’s bus and finally add the cost function (function of the P absorbed by the loads and the maximum surplus available in that time) to be minimized by the algorithm. Am i on the right direction using the direct specification? When i add a new variable how can i refer it specifically to a variable in the mpc (for example the P absorbed by a load)? Sincerely, thank you again for all your help, Davide Da: Ray Daniel Zimmerman<mailto:r...@cornell.edu> Inviato: giovedì 8 ottobre 2020 16:02 A: MATPOWER-L<mailto:matpowe...@list.cornell.edu> Oggetto: Re: Bus, Loads and Generators question H [https://ipmcdn.avast.com/images/icons/icon-envelope-tick-round-orange-animated-no-repeat-v1.gif]<https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient> Mail priva di virus. www.avast.com<https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient>
