Overlapping decomposition and decentralized LQG control for interconnected power systems

In this paper the overlapping decomposition for stochastic systems is presented by using the stochastic inclusion principle. A special attention is paid to the decompositions satisfying restriction, aggregation, and both restriction and aggregation conditions of the inclusion, respectively. Taking a 19th order model for load-frequency control of a two-area power system with overlapping structures as an example, it is shown that the overlapping subsystems of the system are decoupled with balance by the special decompositions, and that the decentralized LQG suboptimal control for the original system is implemented by the proper contraction of the dynamic controllers formulated for the decoupled subsystems.