MODELEX External Network Modeling

Power flow models are used in all areas of steady-state power system network analysis and optimization. Multi-area power flow models are frequently large. In fact, the trend is towards extremely large base models, with 50,000 or more buses. Many parts of such models have little influence on a given type of study, and can be discarded. Still other parts can be replaced by reduced equivalents. The Modelex package provides a means for obtaining such reduced models without sacrificing accuracy. The reduced model is more manageable and computationally efficient.

Modelex enables the engineering user to determine quickly and easily how much of the external system needs to be modeled, either in reduced form or as part of the buffer zone, to give satisfactory accuracy within the designated internal part. Equally, it allows the unwanted parts (e.g. lower voltage levels) of the internal system to be identified and eliminated: an important modern requirement in the modeling of multi-area transfers.

The program offers a range of state-of-the-art method options. It produces equivalents with realistic impedances, which are very much more reliable for modern applications, such as optimal power flow, than with most of the standard industry packages. The program can produce equivalents corresponding to different network loadings and topologies, and merge the results into a single equivalent model. For a given equivalent model, the program can automatically perform a study of the accuracy of the reduced model.

The program also has an option for deriving equivalent balanced fault analysis models, as well as power flow models.

Power Computer Applications, 1921 S. Alma School Road, Suite 207, Mesa, AZ 85210. Tel: 480-345-7600; Fax: 480-345-7601.