See my post of about 10 minutes ago about how to minimize losses. Btw, in the context of an OPF there really is no concept of a "slack" bus. The reference bus serves only as a voltage angle reference, but all generators are free to be redispatched so you don't need a "slack".
-- Ray Zimmerman Senior Research Associate 211 Warren Hall, Cornell University, Ithaca, NY 14853 phone: (607) 255-9645 On Mar 14, 2011, at 5:08 AM, Teddy Richa wrote: > Dear Dr. Zimmerman, > > We are using case30 in Matpower. > > For a fixed load, we added capacitor banks on all buses. > > We performed "runopf" and shut down the capacitor banks that gave very small > values. > We are left with 13 capacitor banks. > > We prepared a code for random load variation of +/- 20% of their initial > value. > > However we did not change the cost of the capacitor banks (we kept it the > same as the cost of the placement) > > We know that P(slack) + P(gen) = P(loss) + P(demand). > > Moreover,P(gen) and P(demand) change together in the same direction and > approximatly at the same rate. > > Hence, to minimize losses we should minimize P(slack). > > How can we change the cost function of capacitor banks and obtain the Optimal > cost at each capacitor bank in such a way to minimize P(slack) and hence > P(losses)? > In other way, how can we relate the cost function to P(slack) > to get minimum losses? > > Thank you for your help! > > Best regards, > > Teddy Richa > >
