Decentralised Control of Strongly Coupled Symmetric Composite Systems

Abstract In the decentralised control of systems which are composed of identical subsystems via symmetric interconnections considerable conceptual simplifications of the design problem can be gained from the conformity of the subsystem behaviour. It is shown that the task of designing a decentralised controllers is equivalent to that of designing a robust centralised controller that simultaneously stabilises two auxiliary plants. The performance of the closed-loop system can be exactly described by a model that includes a decentralised controller with only two control stations. A reasonable model aggregation provides an approximate model which includes merely a centralised controller. The results are illustrated by investigating the decentralised voltage control of an electric power system.