Reduced-order models for dynamic control of power plants based on controllability and observability

A new technique for constructing dynamic equivalents of power systems is developed. The method identifies the important modes of the system utilising a performance index based on the notions of controllability and observability. The system state variables corresponding to the retained modes are identified by inspection of the elements of the sentivity matrix relating the eigen-values to the state variables. The suitability of the method for obtaining reduced-order models of power systems for dynamic-control purposes is demonstrated on a single-machine infinite-bus system. Several reduced-order models are produced and their accuracy discussed.