Research into quasi-decentralised control

Quasi-decentralised control for complex systems is proposed in the paper. Different forms of input-output participation factors (IOPFs) are also introduced mainly to help to determine a suitable decentralised or, if necessary, a quasi-decentralised stabilising scheme. IOPFs can be used to identify practically fixed modes which cannot be detected by the most existing mathematical tools, and to compare the effectiveness of different input-output pairs. The proposed concepts and approaches are illustrated by a power system stabiliser design problem for a sample system. Two other applications of IOPFs and some suggested future research are also presented.