Hi Mirish, I just finished my work that is somewhat related to yours. I did a reactive power dispatch where the Pg of all generators are already known since it is cleared separately in the electricity market. What i did was i set one generator to be a "slack" generator to take up/absorb the changes in losses due to the redispacth of reactive power. I set the Pmin and Pmax of this gen to its true values while the rest of the generators i set to Pg=Pmin=Pmax. It converged for the cases that i worked on.
Vida On Sep 21, 2015 10:57 PM, "Ray Zimmerman" <r...@cornell.edu> wrote: > *First of all, when asking a new unrelated question, please don’t just > reply to a previous message. Start a new thread with a new subject.* > > So, are you saying your are attempting to run an AC OPF problem where Pg > is fixed and Qg are the only free variables? If so, the only way it really > has a chance of working is if the loads and active power generation are > feasible for the AC OPF problem (e.g. you got them from an AC OPF > solution). In that case, the original Qg solution should also be feasible. > However, this is a very constrained problem that may only have a single > feasible solution point (corresponding to the original AC OPF values of > voltage and reactive injection). > > If however, the Pg values and the loads are not guaranteed to be feasible > (i.e. coming from an AC OPF solution), then branch flows may violate their > limits and it may not be possible to dispatch reactive power in a way that > results in system losses exactly matching the difference between specified > load and specified generation. I.e. the problem may be over-specified and > therefore infeasible. > > Ray > > > > On Sep 21, 2015, at 7:45 AM, Mirish Thakur <mirishtha...@gmail.com> wrote: > > Hello MatPower community, > > > I want to analyze monetary consequences of reactive power dispatch on > energy market which is already considering real power prices only. For this > I have data of conventional power plants dispatch for every hour in whole > year and respective variable cost of generation. I’ve active and reactive > power demand for each hour as well. For this case I want to keep generator > dispatch Pg=Pmin=Pmax (no change in active power generation) and Pd and Qd > (real and reactive demand) as per given for whole year. Also I want to keep > RATE_A value constant in opf. But I’m facing convergence problem in runopf. > runopf > doesn’t converge until and unless I make Rate_A value 1.5 times and some > changes in Pmax and Pmin values at input side. Is there any alternate way > to get convergence without making any changes in Pg, Pmax, Pmin and Rate_A > value? (For example any changes in line parameters or something else). > Thank you for your time. > > > Regards > > Mirish Thakur > > KIT University. > > >
