It isn't clear to me whether you are attempting to use MATPOWER's DC OPF or implement your own. Section 3.7 of the User's Manual gives the details of the simplifying assumptions used in MATPOWER's DC power flow modeling.
You can run a DC OPF simply by using the rundcopf() function. -- Ray Zimmerman Senior Research Associate B30 Warren Hall, Cornell University, Ithaca, NY 14853 phone: (607) 255-9645 On Oct 17, 2013, at 4:16 AM, Qi Wang <[email protected]> wrote: > Dear Ray, > > I am trying to convert AC power flow into DC one, to study the relation about > them. > via delete the reactive power variables, reactive power balance equations, > all the voltages are assumed to 1.0 p.u., > and also assume that the angles are too small that sina = a, so sin(a-b) = > (a-b), meanwhile, cos(a-b) = 1. > > But for the admittance matrix, I didn’t ignore the Imaginary part j, I only > consider cosa = 1 and sina = a (rad), is that right? > And the same for the power injection at bus, I write in the way that’ the > power injected into the bus is equal to the power injected from those > branches connected to this bus plus the power injected to the ground from > this bus as the shunt power.’ Also, I only consider cos(a-b) = 1 and sin(a-b) > = (a-b), is that right? > > But unfortunately, when I run the DC model, It returns ‘OPF not solved to > optimality’, It seems very strange. > Do you think are there any wrong about my consideration for DC model change? > And do you have any suggestion about the DC changing, please? > > Best regards, > > Qi Wang > > > > >
