There are an infinite number of ways to modify the inputs to an OPF to achieve a desired change in the flow of power on a given branch. Each one will result in different set of prices. I'm afraid your problem is not well-defined.
Maybe you really want to look at changing the line limit (RATE_A) on lines that are at 100% of their capacity? -- Ray Zimmerman Senior Research Associate 419A Warren Hall, Cornell University, Ithaca, NY 14853 phone: (607) 255-9645 On Apr 3, 2013, at 6:00 PM, Yahook K <[email protected]> wrote: > Respected Sir, > > Thank you very much for your reply. > > My 3rd question is : I want to change the saturation percentage of a certain > branch A (for example, from the original 50% to 120% or 98%)to see its > influence to the LMP price of all the buses. That is, I want to see the > transmission line congestion impacts on the LMP price. > > How to achieve that? > > In my opinion, to achieve that, I want to change the power demand > quantity(PD) of a certain bus B, so that the saturation percentage of branch > A will change to 120% or 98%. Then, I runopf to check the Lamda P price and > compared the Lamda P price with the previous price when the saturation > percentage of branch A is 50%. Am I right? > > Please shed light on me. Thanks. > > > From: Ray Zimmerman <[email protected]> > To: MATPOWER discussion forum <[email protected]> > Sent: Wednesday, April 3, 2013 9:39 AM > Subject: Re: saturation of the branch > > Table B-3 in the User's Manual (or help caseformat) describes the fields of > the branch matrix. RATE_A is the limit used by runopf(). Please note that for > an AC power flow model it is an MVA limit, and for DC power flow it is a MW > limit. So that saturation percentage as you call it would be … > > define_constants; > if <AC power flow> > saturation = sqrt(results.branch(:, PF).^2 + results.branch(:, PT).^2) ./ > results.branch(:, RATE_A); > else > saturation = abs(results.branch(:, PF)) ./ results.branch(:, RATE_A); > end > > I'm afraid I don't understand your 3rd question. > > -- > Ray Zimmerman > Senior Research Associate > 419A Warren Hall, Cornell University, Ithaca, NY 14853 > phone: (607) 255-9645 > > > > > On Apr 3, 2013, at 1:18 AM, Yahook K <[email protected]> wrote: > >> Respected Sir, >> >> From mpc.branch, I can get the From bus injection and the To bus injection >> of each branch. But how can I calculate the saturation percentage of the >> branch? For example, the branch has a limit of 15 MW, and there are 5 MW >> flowing in this branch. I think to calculate the saturation percentage we do >> 5/15=1/3 >> >> Another question is where to find the limit for each branch? >> >> The third question would be if I wanna set the branch saturation percentage >> to 50%, 90% 120%, break. How can I do it? Can you give me some guidance? >> >> Please shed light on me. Thank you. >> >> > > >
