It is susceptance, not capacitance, so the first sentence in section 3.2 needs to be fixed (and will be in the final MATPOWER 5 release). Thanks for catching this.
-- Ray Zimmerman Senior Research Associate B30 Warren Hall, Cornell University, Ithaca, NY 14853 USA phone: (607) 255-9645 On Oct 15, 2014, at 5:52 AM, Kaiser, Raphaël <[email protected]> wrote: > Dear all, > > I have a questions concerning the modelling of branches and I'm > referring to the MATPOWER 4.0b1 User's Manual. > > 1. In chapter 3.2 the first sentence states: > All transmission lines, transformers and phase shifters are modeled with > a common branch model, consisting of a standard π transmission line > model, with series impedance z_s = r_s + jx_s and total charging > capacitance b_c , in series with an ideal phase shifting transformer. > Note: b_c is defined as *total charging capacitance*. > > 2. In chapter 3.5 the letter b is used in the formula y_sh = g_sh + jb_sh > Note: In this context, b seems to be used as a *susceptance*. > > 3. In Appendix B, Table B-3 on page 79 I cannot find any capacitance, > but there is the *total line charging susceptance (p.u.)* in column 5. > > As susceptance and capacitance are related but not the same, the > statements of the manual seem contradictory to me. What does b in the > common branch model stand for, the capacitance or the susceptance? > > Best regards, > Raphaël Kaiser > > >
