Various Mixed Approaches of Model Order Reduction

In present analysis, mixed approximation techniques for achieving a reduced order model of LTI single input-single output system are implemented to an eighth order system. The numerator polynomials of higher order system are reduced by Pade approximation and factor division algorithm while denominator polynomial of the higher order system are reduced by modified pole clustering, stability equation method and Routh stability method. Among three mixed techniques under consideration, Pade approximation-modified pole clustering gives the best result when compared to other mixed reduction techniques.