%0 Journal Article %T Passivity and passivation of interconnected time-delay models of reheat power systems %A Magdi S. Mahmoud %A Abdulla Ismail %J Mathematical Problems in Engineering %D 2006 %I Hindawi Publishing Corporation %R 10.1155/mpe/2006/90416 %X This paper investigates the problems of delay-dependent passivity and passivation of a class of linear interconnected time-delay systems with particular emphasis on multiarea reheat power systems. This class contains state delay in the dynamics and observation at the subsystem (local) level. A new state transformation is developed to exhibit the delay dependence in the system dynamics and a less conservative passivity-bounding inequality is incorporated. Through the analytical development, it is established that the passivity condition can be cast in a linear matrix inequality (LMI) format at the subsystem level thereby facilitating decentralized passivity analysis. For state-feedback passivation, it is proven that it is indifferent to use instantaneous or delayed decentralized state feedback. The case of dynamic output-feedback passivation is also treated. The analytical developments are simulated to a typical multiarea power system and the ensuing results show satisfactory performance. %U http://www.hindawi.com/journals/mpe/2006/090416/abs/