Distributed Fault Estimation and Fault-Tolerant Control of Interconnected Systems With Plug-and-Play Features

This paper is concerned with distributed fault estimation and fault-tolerant control for interconnected systems. Based on the local and interconnected information relevant to neighbors, a distributed fault estimation observer (DFEO) is constructed in a fully distributed fashion for each subsystem. The generated estimation errors are decoupled with external disturbances such that the DFEO has an asymptotical estimation feature. Then, using the estimated state and fault, a fault compensation based distributed fault-tolerant control (DFTC) law is designed for each subsystem. Sufficient conditions in the form of linear matrix inequalities (LMIs) are presented to guarantee the closed-loop system's properties of stability and disturbance attenuation. Moreover, the proposed DFEOs and DFTC laws allow subsystems to be added or removed in a plug-and-play (PnP) fashion, which enhances the scalability of interconnected systems. Finally, the effectiveness and performance of the proposed method are demonstrated through simulations conducted on the power network system (PNS).