thanks a lot Álvaro, I greatly appreciate fopr helping undertsnad more on the DC opf. If you don't mind, i would like to ask further in reference to the first question in my previous mail, i.e. * 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)
*I have failed to really get clearly which of the two programing methods (LP or QP) MIPS uses, specifically for AC problems with quadratic cost functions. (All my simulations are AC). * * On 10 December 2012 17:12, Álvaro Jaramillo Duque < [email protected]> wrote: > 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 > -- *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* ** ****
