Effect of nonuniformity on the continuous representation of electromechanical dynamics in large power systems

The purpose of this note is twofold. First, it brings to the attention of the readers the work by A. Semlyen (see IEEE Trans. Power Appar. Syst., Vol.PAS-93, no.2, p.676-84, 1974) with essentially the same subject matter as the work of J.S. Thorp et al. (see ibid., vol.18, no.1, p.49-50, 1998), namely the representation of a large power system-from the point of view of its electromechanical dynamic behavior-as a distributed continuum. Semlyen predates Thorp by a quarter of a century. Second, it points to a detail by Thorp needed to render it truly nonisotropic as opposed to the homogeneous and isotropic modeling used in the approach adopted by Semlyen.