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!
[mailto:bounce-120786918-76238...@list.cornell.edu] On Behalf Of Muhammd Ali
Sent: 14. september 2016 17:19
To: MATPOWER discussion forum <matpowe...@list.cornell.edu>
Subject: Re: benefit function of dispatchable load
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???
On 9/14/16, Samuel Perkin <samu...@landsnet.is> 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
> 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,
> -----Original Message-----
> From: bounce-120786253-76238...@list.cornell.edu
> [mailto:bounce-120786253-76238...@list.cornell.edu] On Behalf Of
> Muhammd Ali Mohseni
> Sent: 14. september 2016 14:56
> To: firstname.lastname@example.org
> 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
> " 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
> 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;