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. (C) 1999 Elsevier Science Ltd. All rights reserved.