Overlapping decentralized control design based on dynamic output feedback for large-scale interconnected systems with longitudinal structure

Robust overlapping decentralized control method based on dynamic output feedback is proposed for a class of large-scale interconnection systems with longitudinal structure. Firstly, the interconnection system with longitudinal structure is decomposed by using inclusion principle of large-scale systems according to special overlapping structure decomposition. The original space is expanded, and a series of pair-wise subsystems are obtained in the expanded space. Then, the robust decentralized controllers based on dynamic output feedback for each pair-wise subsystem are designed by using LMI method and Lyapunov theory. Finally, these controllers are contracted back to the original space. Overlapping decentralized control laws of the original system are obtained, and so that the original system is robust connectively stable. The proposed method can avoid the difficulty in solving LMI with high dimension caused by too many subsystems. It is applied to AGC control design of a three-area interconnected power system with longitudinal structure. And the simulation results are compared with the one by using LMI method directly. The results show that the performances of the designed controllers using proposed method are better. The effectiveness and feasibility of the proposed method is proved.