OICC Press Majlesi Journal of Electrical Engineering 2345-3796 9 1 2024 02 20 Model Order Reduction by Legendre Expansion Using Harmony Search Algorithm EN Hasan Nasiri Soloklo Shahid Bahonar University of Kerman Malihe Maghfoori Farsangi Shahid Bahonar University of Kerman Journal Article 2024 02 20 In this paper, a new approach is investigated for order reduction based on Legendre expansion. Harmony Search is used in this approach, to determine the reduced order model's parameters. The Routh criterion is applied to specify the stability conditions. Then, the stability conditions are constraints in optimization problem. To present the efficiency of the proposed method, three test systems are reduced. The obtained results were compared to other existing techniques. The comparison showed that the proposed approach performs well.