Dear Fred

I will try to answer between the lines

On Sun, Dec 9, 2012 at 6:20 PM, Fred Kanjelesa <[email protected]> wrote:

> I am using MATPOWER to run OPF for a 60 bus network modeled based on a
> real power system. the output window indicates MIPS is the solver used and
> converges in quite a few iterations.
>
*Question 1*
> what i do not understand is whether MATPOWER uses Quadratic Programing
> (QP) for power systems defined with quadratic generation cost functions or
> it uses Linear Programing (LP)
>

See the manual section 5.2

"5.2  Standard DC OPF
When using DC network modeling assumptions and limiting polynomial costs to
second order, the standard OPF problem above can be simplified to a
quadratic
program, with linear constraints and a quadratic cost function. In this
case, the
voltage magnitudes and reactive powers are eliminated from the problem
completely
and real power flows are modeled as linear functions of the voltage
angles..."

*Question 2*
> If it uses LP is there a way of knowing in how many linear segments the
> polynomial/quadratic cost function is converted to linearize it?
>

You have to set in the options "DC model". Then MATPOWER will preform what
is described in section 5.2

About the number of segments of the cost function, I don know how to get
that information.


>
> *Question 3*
> Is there a way of knowing the confidence level of the results obtained
> from an OPF MATPOWER simulation, i.e. a value or something to use one can
> use to convince others the certainity of the results.
>
>
I think the easy way to compere the performance of a OPF is with the value
of the cost function. If you get lower value, this solution is better in
economical terms.



> i will be very grateful for help with this.
>
>
> --
> *Fred Kanjelesa.*
> KU/Nepal.
>
> Home (Zambia):  +260967753320
>
> "Go as far as you can see. When you get there, you'll be able to see
> farther!" *Thomas Carlyle* ** ****
>

I hope I have been helpful, best regards.

Álvaro Jaramillo Duque

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