Oh God, I'm confused. Thank you so much for enlightening me! Thank you!
Yansong Li 2015/03/26 在 2015-03-26 21:09:52，"Ray Zimmerman" <[email protected]> 写道： Is there a reason that a single OPF with the combined system, including the tie line, doesn’t do what you want? That should minimize cost of operation of the entire system, taking into account the effect of losses in all lines, including the tie line. Ray On Mar 26, 2015, at 4:29 AM, 李岩松 <[email protected]> wrote: It’s an AC model and I want to tie two independent grids together, which are a bit far from each other. As the tie line is much longer than the lines inside each grid, I should take the power or loss on the tie line into account so as to avoid the case that the power flow on the tie line is only 0.01 p.u. which maybe uneconomic. If it’s not attainable by using OPF, I'm wonding if I can use GA or PSO for optimizing by calling PF of matpower in the process to add Ptie-loss in the object. Appreciate your help and thanks so much. Yansong Li 2015/3/26 At 2015-03-23 23:52:40, "Ray Zimmerman" <[email protected]> wrote: The power flow in branch 3 is not an optimization variable, so you need to express your cost as a function of the optimization variables. For an AC power flow model, this is non-linear, so that’s problematic. For a DC power flow model, however, the flow is a linear function of the angles so you can apply a user-defined cost to it. I suggest you take a look at toggle_softlims.m for an example of code that puts a cost on the flow that exceeds a threshold. What you want to do is nearly identical (for the DC case), except that your threshold would be zero and you are only doing it for a specific line. Ray On Mar 20, 2015, at 8:59 AM, 李岩松 <[email protected]> wrote: Dear All: I have studied the ‘6.3 Extended OPF Formulation’ and '7 Extending the OPF’ in ‘manual.pdf’ to include additional cost in the function but failed to figure it out. The default objective function is the total cost of all the generators per hour. Now I want to add ‘Pbranch3*ξ’, in which Pbranch3 is the active power transferred on branch 3 and ξ is the electricity price which is a constant. <截图1.png> With greatest pleasure to get any response. Yours sincerely Yansong Li 2015/03/20
