Decentralised nonlinear H∞ excitation control based on regulation linearisation

Based on a combination of regulation linearisation and H_∞ theory, a novel nonlinear robust optimal excitation control for multimachine power systems is presented. The feedback variables of the derived control law are completely local measurements. Simulations performed on a 6-machine system demonstrate that the proposed nonlinear H_∞ excitation controller is more effective than other types of excitation controllers for improving both dynamic performance and the stability of power systems suffering from large disturbances. In addition, the H_∞ control for a regulation linearisation system is equivalent to a nonlinear H_∞ control for the original nonlinear control system in the sense of a type of L₂-gain