Decentralised sliding-mode control for multimachine power systems using only output information

A robust stabilisation problem for multimachine power systems is considered using only output information. The power system is formed from an interconnected set of lower-order systems through a transmission network which is nonlinear and has an associated nonlinear bound. Uncertainty in the input distribution matrices of the subsystems and mismatched uncertainty associated with the interconnections are both considered. Under some mild conditions, a decentralised sliding mode control scheme is developed. The conservatism of the results obtained is reduced by fully using the system output information and the structure of the uncertainties. Simulation results for a three-machine power system are presented to show the effectiveness of the proposed method.