Dynamic Reduction of Power Systems Using a Simple Equivalent

Recently, a simple dynamic equivalent for a power system external area containing a group of coherent generators was proposed in the literature. This equivalent is based on a new concept of decomposition of generators and a two-level generator aggregation. With the knowledge of only the passive network model of the external area and the total inertia of the generators in this area, the parameters of this equivalent are determinable from a set of measurement data taken solely at a set of boundary buses which separates this area from the rest of the system. The formation of this equivalent, therefore, does not require any measurement data at the external area generators. This is an important feature of this equivalent. In this paper, the use of this equivalent is explained with illustration, and some interesting new results on its performance are presented with varying coherency tolerances and external area sizes