Dynamic Equivalent Power System Models

This paper discribes the use of identification methods for the determination of dynamic equivalent models of portions of a power system. The resulting models are linear models for use in stabilizer design and dynamic stability studies. Data for the models are obtained from a transient stability program where small perturbations of the complex voltage on a bus are made, and the resulting complex currents are measured. Using the above data and linear system identification techniques, linear models are obtained relating the complex current to the complex voltage on the bus. The power system as seen from the bus may then be replaced by the model. An example system of 59 machines and 63 buses is used to demonstrate the method[l].