I think he may be referring to the real and imaginary parts of the line propagation constant gamma ( https://en.wikipedia.org/wiki/Propagation_constant). Note that this is a distributed parameter (i.e., per unit length of the line), while the parameters given in the *.m file are supposed to be lumped parameters.
Strictly speaking, you cannot recover the value of alpha and beta unless you know how the lumped parameters were obtained from the distributed ones. If you assume that they were simply obtained by multiplying the manufacturer's per-unit-length values by the length of the line (which is only valid for "short" lines), *and* if you knew such length, then you could obtain alpha and beta very easily. It's described in Kundur's book, Chapter 6.1.4. Schematically, in pseudo-code: r = R / length x = X / length bshunt = Bshunt / length alpha + j beta = sqrt ( (r + j x) * j bshunt) -- Jose L. Marin Grupo AIA 2017-05-30 22:22 GMT+02:00 Ray Zimmerman <[email protected]>: > The model used for the transmission line shown in Figure 3-1 in the User’s > Manual. I’m not sure what you mean by the α and β of the transmission line. > What do these parameters refer to? > > Ray > > > > > On May 28, 2017, at 10:04 PM, Ameeratul Balqis < > [email protected]> wrote: > > > > Hello and good day, > > > > I have been using command of 'runpf(casedata)' in MATPOWER in order to > get the power flow of the system case. However, I realized that the result > did not include the α and β of each transmission line. > > > > 1.How can I get the α and β of each transmission line? What command > should I use? > > 2.What is the .m file in order for me to able to learn more or edit the > equation of the α and β in the lines. > > > > I'm new in using MATPOWER so I hope I would get help and guidance > regarding the above problem I've stated. > > > > Thank you > > > >
