Numerical Testing of Power System Load Flow Equivalents

Twenty one different versions of four topological load-flow equivalencing approaches have been tested on a number of power systems. From these tests, it has been possible to ascribe some general properties, in terms of accuracy and conditioning, to the equivalents. Several new and very competitive versions were developed during the work, and are presented here. The results of the tests provide a strong guide to the choice of specific equivalents for practical on- and off-line applications.