Hi Ray, The only definition I was able to find is from the lecture slides of Professor Tom Overbye at Texas A&M University:
https://overbye.engr.tamu.edu/wp-content/uploads/sites/146/2018/10/ECEN615_Fall2018_Lect17.pdf#page=11 *LCDF_ij is the portion of the active power flow in branch j (the flow that will occur when the branch j is closed (which we do not know)) that is distributed to branch i due to the closure of branch j.* Using the negative of the post-closure LODF makes sense to me, but the slides mention the insertion of an "additional basic transaction" that I couldn't quite understand. Perhaps it refers to reinstating the open branch before computing the LODF. I will try testing against results from PowerWorld and see if the -LODF approach works. Richard On Wed, 31 Aug 2022 at 22:57, Ray Daniel Zimmerman <[email protected]> wrote: > Hello Richard, > > Do you know the precise definition of the LCDF? > > The LODF_*ij* is the change in flow in branch * i* resulting from a > branch *j* outage as a fraction of the pre-outage flow on branch *j*. So > would the LCDF_*ij* be the change in flow in branch *i* as a result of a > branch *j* clousre as a fraction of the post-closure flow on branch *j*?* > If so, it would seem that the LCDF is equal to the negative of the LODF > computed on the post-closure network, right? > > I suspect there is a more efficient way to compute LCDFs if you already > have the PTDFs for the pre-closure system, but I haven’t found a formula > for it or derived it myself (yet). > > Ray > > * Seems that’s exactly how PowerWorld describes it on page I11-19 of this > Linear Analysis trainman document > <https://www.powerworld.com/files/TrainingI11LinearAnalysis.pdf>. > > > On Aug 30, 2022, at 10:12 AM, Richard Lincoln <[email protected]> > wrote: > > I am able to use the makeLODF function from MATPOWER to calculate the > changes in flows given the outage of a branch. However, I would like to be > able do the same, but for the reconnection of a branch that is presently > open. > > I've heard these referred to as Line Closure Distribution Factors (LCDF). > Does anyone know how they might be computed with MATPOWER? > > Richard > > >
