Thank you very much Prof. Ray. Regards Mirish
On Fri, Sep 25, 2015 at 7:37 PM, Ray Zimmerman <r...@cornell.edu> wrote: > You might have a look at Markets for Reactive Power and Reliability: A > White Paper <http://e3rg.pserc.cornell.edu/node/100>. > > Ray > > > > On Sep 24, 2015, at 7:36 AM, Mirish Thakur <mirishtha...@gmail.com> wrote: > > Thank you Dr. Ray and Vida. I think there might be mismatch between > generation and demand which I need to check out through database and may > be unvalid standard position of taps which may cause the problem. So my > approach is to minimize reactance values of transformers (at distribution > side which are connected to lower voltage 110 KV bus) and set tap position > default as 1 at input side in modeling which I hope will give better > results. Another thing I want to ask you Vida can you suggest me any > literature for reactive power pricing methods. Right now I'm focusing on > 1) Triangular relationship between active and reactive power approach 2) > opportunity cost method. Thanks for your time. > > Mirish Thakur > KIT University. > > On Tue, Sep 22, 2015 at 3:20 AM, vids <vidaj...@gmail.com> wrote: > >> 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. >>> >>> >>> > >
