Decentralised nonlinear H-infinity control for stability enhancement in power systems

A method for designing the decentralised H-infinity excitation control of a generator in power systems is presented. The proposed controller is utilis ed to damp inter-area oscillations and enhance power system stability. The decentralised controller design procedure for nonlinear systems is presente d using the Hamilton-Jacobi inequality approach. The control is local or de centralised, in the sense that the controller depends only on the informati on available locally. The effectiveness of the proposed decentralised H-inf inity controller is demonstrated through digital simulation studies on a tw o-machine power system. The digital simulation studies are conducted using the PSCAD/EMTDC software package. The simulation results show that the cont roller contributes significantly to the damping of interarea oscillations a nd the enhancement of power system stability under a wide range of operatin g conditions.