A New Delay Dependent Robust Fixed-Order Decentralized Output Feedback   LFC Design for Interconnected Multi-Area Power Systems
  This paper presents a novel load frequency control (LFC) design using integral-based decentralize fixed-order perturbed dynamic output tracking scheme in a delay dependent nonlinear interconnected multi-area power system via LMI approach. The tracking controller is designed such that the effects of the parameter variations of the plant and dynamic output controller as well as load disturbances are minimized. The inputs and outputs of each controller are local, and these independent controllers are designed such that the robust stability of the overall closed-loop system is guaranteed. Simulation results for both two- and three-area power systems are provided to verify the effectiveness of the proposed design scheme. The simulation results show that the decentralized controlled system behaves well even when there are large parameter perturbations and unpredictable disturbances on the power system. 
Ali Azarbahram, Mahdi Sojoodi, Mahmoud-Reza Haghifam
math.OC