Multi-objective Weighted Sum Approach Model Reduction by Routh-Pade Approximation using Harmony Search

A new weighted-sum multiobjective approach is investigated for order reduction based on Routh--Padé approximation, in which the harmony search algorithm is used to optimize the reduced-order model s parameters. In this method, apart from minimizing the errors between a set of subsequent time moments/Markov parameters of the system and those of the model, the error between the singular values of the reduced-order system and those of the original system is minimized. The Routh criterion is applied for specifying the stability conditions. The stability condition is then considered as a constraint in the optimization problem. To present the ability of the proposed method, 3 test systems are reduced. The results obtained show that the proposed approach performs well.