Dear Samuel, thank you very much, now I understand what happen
With respect, Ali On 9/15/16, Samuel Perkin <[email protected]> wrote: > Dear Muhammd, > > The coefficients of the cost function should be positive (see Figure 6-5 in > the Matpower manual), and as dispatchable load is modelled as negative > generation your cost value will be negative (i.e. a benefit). The OPF aims > to minimize costs (or maximise negative costs) the model will now correctly > aim to increase load as much as is economically feasible. > > In short, what you have now is correct! > > Kind regards, > > Samuel > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Muhammd Ali > Mohseni > Sent: 14. september 2016 17:19 > To: MATPOWER discussion forum <[email protected]> > Subject: Re: benefit function of dispatchable load > > Dear Samuel, > > I don't have any other problem. It is interesting when I change the benefit > function coefficient to positive like this: > mpc.gencost = [ > ..... > 2 0 0 3 0.5*0.015 13.0 0; > ....] > there isn't any warning and DC Opf converge!!! now results is true???!!! > hence the power associated with dispatchable Loads is negative but first > part of cost function is positive(0.5*0.015*P^2>0)!!!!!! Is the final value > of Opf correct??? > > With respect, > > Ali > > On 9/14/16, Samuel Perkin <[email protected]> wrote: >> Dear Muhammd, >> >> Your error message is not really an error, but is just a warning >> statement that you shouldn't need to react to. It simply means that >> the optimisation algorithm doesn't require an initial guess of the >> solution, and therefore any initial guess is ignored. This warning >> message isn't related to dispatchable loads. Did you get any other error >> messages? >> >> Your input for dispatachable load looks fine to me, except I think >> Qmax (column 4) should probably be 0 to prevent your loads from acting >> as 'reactive generators'. >> >> Kind regards, >> >> Samuel >> >> -----Original Message----- >> From: [email protected] >> [mailto:[email protected]] On Behalf Of >> Muhammd Ali Mohseni >> Sent: 14. september 2016 14:56 >> To: [email protected] >> Subject: benefit function of dispatchable load >> >> Dear all >> According to the Matpower manual (6.4.2 Dispatchable Loads) approach >> to dispatchable loads is to model them as negative real power >> injections with associated negative costs. but when I run dcopf I got this >> error!!! >> >> " MATPOWER Version 6.0b1, 01-Jun-2016 -- DC Optimal Power Flow The >> interior-point-convex algorithm does not accept an initial point. >> Ignoring X0." >> >> I set negative output, ranging from 0 to -1000 like this mpc.gen = [ >> ..... >> 1 0 0 100 -100 1.05 100 1 0 -1000 >> 0 0 0 0 0 0 0 0 0 0 >> 0; >> ....] >> also I assume that bid function of load like this : aP+ b and benefit >> function of load : 0.5aP^2+bP >> >> mpc.gencost = [ >> ..... >> 2 0 0 3 -0.5*0.015 13.0 0; >> ....] >> >> > >
