A New Decentralised Controller Design Method with Application to Power System Stabiliser Design

It is known that decentralised stabilising controller design for a large-scale system can be translated into an equivalent problem of decentralised controller design for a multi-input multi-output (MIMO) control system. This paper shows that, subject to a condition based on the structured singular values, each local controller can be designed independently. The stability condition for the overall system can be easily stated as the achievement of a sufficient interaction margin, introduced in earlier work, together with a sufficient gain and phase margin, defined using classical feedback theory during each independent design. The suggested design approach is applied to the decentralised design of a power-system stabiliser for a model of a practical 10-machine power system. The potentials and limitations of the suggested design approach in its current form, and possibilities for further research, are also discussed in this paper