A robust decentralized approach to the multiarea frequency control of power systems

It is an important problem in multiarea power systems to attenuate the frequency deviation due to load change. Since power systems are spatially dispersive, decentralized control is more practical than lumped control. In this paper, we propose two robust decentralized control schemes for this problem. The difficulty with this problem is that the linearized model of a multiarea power system with frequency deviations as outputs is a MIMO system that has a transmission zero at s = 0. They key idea is to change the output of one subsystem so that the resulting new plant does not have any zero at s = 0. The new outputs are chosen carefully so that the regulation of the new outputs can guarantee the regulation of all frequency deviations and tieline power. Further, parameter uncertainty is taken into account in the controller design to achieve robustness. Simulation shows that the proposed methods are effective. (C) 2002 Wiley Periodicals, Inc.