A Reduced Order Model for AGC System using Routh Approximation Technique

The fast development and usage of small digital computers and processors in the design, analysis and implementation of suitable control strategies has led towards proposing the reduced order modeling of large order physical systems. As most of the models are too complex to be analyzed in its original form, various techniques have been developed in the past to reduce the order of a complex system. The structure of existing power systems is very complex in nature and therefore their resulting mathematical models are of large orders. The analysis of such systems becomes a tedious and difficult job. In this article, a model order reduction technique based on Routh approximation criteria is used to model AGC model of a single area. An AGC model of single area is reduced to third order. The system dynamic response plots for both original and reduced order models are obtained for step input and they are compared. The investigations of these results carried out in the study demonstrate that the complexity of the system is reduced to a great extent. However, the dynamic behavior of all the system states for same step disturbance is within acceptable limit.