Available online at www.sciencedirect.com Journal of the Franklin Institute 351 (2014) 3286–3304 H 1 optimization-based decentralized control of linear interconnected systems with nonlinear interconnections Ali Sghaïer Tlili a,b,n , Naceur Benhadj Braiek b a Faculty of Engineering, Northern Border University, P.O. Box: 1321, Arar, Kingdom of Saudi Arabia b Laboratoire de Systèmes Avancés (LSA), Ecole Polytechnique de Tunisie, BP. 743, 2078 La Marsa, Tunisia Received 18 July 2013; received in revised form 16 January 2014; accepted 13 March 2014 Available online 21 March 2014 Abstract The focus of this paper is on the design of a H 1 decentralized observation and control approach for a class of nonlinear disturbed interconnected systems. The proposed scheme is formulated as an optimization problem in terms of linear matrix inequality (LMI) to compute the robust observation and control gain matrices simultaneously, to maximize the bounds on the nonlinearity which the system can tolerate without going unstable, to improve the performance of the proposed control strategy by minimizing the H 1 criterion and to ensure the stability of the closed loop system in the Lyapunov framework despite the exogenous disturbances applied to the subsystems. A simulation is provided on a 3-machine power system, which generators are strongly nonlinear interconnected, to show the efficiency of the designed approach. & 2014 The Franklin Institute. Published by Elsevier Ltd. All rights reserved. 1. Introduction Decentralized control of interconnected systems has received considerable attention in recent years due to its challenging features and practical applications such as mobile robots [1,2], inverted pendulums [3,4], aerospace vehicles [5,6], network of Chua's chaotic circuits [7], biochemical applications [8], mass-dashpot systems [9], and power systems [10,11]. So far, many works dealing with the decentralized control approach involving stabilization and model www.elsevier.com/locate/jfranklin http://dx.doi.org/10.1016/j.jfranklin.2014.03.005 0016-0032/& 2014 The Franklin Institute. Published by Elsevier Ltd. All rights reserved. n Corresponding author. E-mail addresses: ali.tlili@ept.rnu.tn (A.S. Tlili), naceur.benhadj@ept.rnu.tn (N. Benhadj Braiek).