H∞ excitation control of multimachine power systems considering delay and disturbances

H_∞ excitation control using energy-based Lyapunov method is suggested for multimachine power systems with transfer delay and disturbances. Under pre-feedback technique, the multimachine power systems are expressed as a dissipative Hamiltonian system. Then the H_∞ controller of excitation of generators connected to distant power systems with time-delay is designed. some sufficient conditions are proposed to guarantee the rationality and validity of the proposed control law, which are derived based on Lyapunov functional method. The closed-loop systems under the control law is asymptotically stable independent of the time delay. Simulation of a two-machine power system shows the effectiveness of the results proposed in this paper.