Yeah, Thanks so much sir. Do you have any idea of how of to add valve point effect in the mpc.gencost data? Presently, our Objective function is mainly a*P^2+b*P+c. But if we want to include the valve point effect i.e. a*P(i)^2+b*P(i)+c+abs(e(i)*sin(f(i)(Pmin(i)-P(i))). Can this be added in the MATPOWER??
On Sat, Jul 15, 2017 at 6:25 PM, Sarmad Hanif < [email protected]> wrote: > I would not say real power minimization, I think it is better to say > active power cost minimization. > > *From:* [email protected] [mailto: > [email protected]] *On Behalf Of *Akash Tyagi > *Sent:* Saturday, 15 July, 2017 8:51 PM > > *To:* MATPOWER discussion forum > *Subject:* Re: Objective Functions > > > > Thanks a lot. > > It is working now. > > The last thing I want to ask is if we don't add reactive cost data to > case, then it is considering only the real power minimization?? > > > > On Sat, Jul 15, 2017 at 6:01 PM, Sarmad Hanif < > [email protected]> wrote: > > From Generator Cost Data table of the MATPOWER manual: > > “If gen has ng rows, then the first ng rows of gencost contain the costs > for active power produced by the > > corresponding generators. If gencost has 2ng rows, then rows ng + 1 > through 2ng contain the reactive > > power costs in the same format.” > > > > Since there are only active power cost terms in the case file and you have > put all active power cost terms to zero, your cost function will evaluate > to zero. > > First add reactive power cost term rows and then specify their marginal > values to be able for MATPOWER to consider them. > > Hope it helps. > > Sarmad > > > > *From:* [email protected] [mailto: > [email protected]] *On Behalf Of *Akash Tyagi > *Sent:* Saturday, 15 July, 2017 7:46 PM > > > *To:* MATPOWER discussion forum > *Subject:* Re: Objective Functions > > > > After putting the cost term of the real power to zero in the mpc.gencost > field, as attached the case below- > > Then after running the optimal power flow by using the following code- > > clc > > clear > > close all; > > define_constants; > > mpc=loadcase(newcase5); > > results=runopf(mpc); > > The objective function is coming zero.?? > > I am not getting this?? > > > > On Sat, Jul 15, 2017 at 10:19 AM, Sarmad Hanif < > [email protected]> wrote: > > Hi, > > Mr. Kardos already gave the references for you to explore the cost > functions in detail. > > A quick fix: > > If you just want to minimize reactive power, then just put cost terms of > the real power to zero in its approriate mpc.gencost field J > > > > Btw, minimizing objective function can mean anything, as it depends on > your “function”. It cannot always mean considering only the reactive power, > as you mentioned in your previous email. > > > > Thanks, > > Sarmad > > > > *From:* [email protected] [mailto: > [email protected]] *On Behalf Of *Akash Tyagi > *Sent:* Wednesday, 12 July, 2017 4:59 PM > *To:* MATPOWER discussion forum > *Subject:* Re: Objective Functions > > > > Hello, > > The obj_func mainly minimizes the cost including the real and reactive > power. > > But I have to only minimize objective function i.e. cost considering only > the reactive power. > > I tried the way explained by you above but I am not able to do this.? > > Can you help? > > basically, my goal is to change the objective function. > > Thanks > > > > On Wed, Jul 12, 2017 at 1:49 PM, Akash Tyagi <[email protected]> > wrote: > > ok, thanks > > > > On Wed, Jul 12, 2017 at 1:40 PM, Kardoš Juraj <[email protected]> wrote: > > Try to have a look in the code in opf_costfcn.m and compare it with the > objective function definition in the manual (http://www.pserc.cornell.edu/ > matpower/manual.pdf) section 6.1 equation (6.6). You will find the > function implemented in the code, as well as its gradient and Hessian > w.r.t. vector x (equation 6.5). If you have problems with derivatives, have > a look at section 6 in this document http://www.pserc. > cornell.edu/matpower/TN2-OPF-Derivatives.pdf. It describes how the first > and second derivatives can be computed. Good luck! > > ========================== > Juraj Kardos > Advanced Computing Laboratory > Institute of Computational Science > Universita della Svizzera italiana > Via Giuseppe Buffi 13 > Lugano 6904 > Switzerland > http://www.ics.inf.usi.ch > =========================== > > > > On 12 Jul 2017, at 09:46, Akash Tyagi <[email protected]> wrote: > > > > Can you explain me through simple example.? > > > > On Wed, Jul 12, 2017 at 1:09 PM, Kardoš Juraj <[email protected]> wrote: > > Hello, > > > > as far as I know, you can define arbitrary objective function by modifying > the following source file: opf_costfcn.m. Don’t forget that you need to > provide gradient and Hessian w.r.t. OPF control variables as well. These > derivations are used in optimizers to find the optimal solution. > > > > Best regards, > > > > ========================== > Juraj Kardos > Advanced Computing Laboratory > Institute of Computational Science > Universita della Svizzera italiana > Via Giuseppe Buffi 13 > Lugano 6904 > Switzerland > http://www.ics.inf.usi.ch > =========================== > > > > On 12 Jul 2017, at 08:02, Akash Tyagi <[email protected]> wrote: > > > > Hello everyone, > > I am working on congestion management and running optimal power flow. > > The Objective function after running the OPF is the cost, but I want to > include my own objective function. > > Can you please let me know how to remove the existing objective function > and include my own objective function. > > Thanks in advance > > > > > > > > > > > > > > >
