Variable structure controller design for large-scale systems

In this paper, a new formulation for controlling large-scale linear, discrete time, and dynamically interconnected system is presented. The large-scale system is decomposed into N subsystems, each satisfying a required performance index criterion. A suboptimal variable structure controller was designed for each subsystem in a decentralized manner to compensate uncertain effects in the interconnection matrix. This controller was designed off-line based on a set of expected system failure modes and switched online when failure detected. This methodology has the advantage of achieving overall system stability robustness for large-scale systems