Dear Samuel,

thank you very much, now I understand what happen

 With respect,

  Ali

On 9/15/16, Samuel Perkin <samu...@landsnet.is> 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: bounce-120786918-76238...@list.cornell.edu
> [mailto:bounce-120786918-76238...@list.cornell.edu] On Behalf Of Muhammd Ali
> Mohseni
> Sent: 14. september 2016 17:19
> To: MATPOWER discussion forum <matpowe...@list.cornell.edu>
> 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 <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
>> 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: 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: matpower-l@cornell.edu
>> 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;
>> ....]
>>
>>
>
>

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