H ∞ analysis method for the small signal stability of power system

This work is concerned with the small signal stability problem in multi-machine systems. By means of H∞ theory, firstly the math model with disturbances is constructed; and secondly, the excitation control law for each generator is designed based on solving Riccati equation. Finally, simulations performed on 4-machine system shows that the proposed H∞ method has more advantages over LQR method in both damping ratio and H∞ norm of the corresponding closed-loop system and so can enhance the small signal stability of power system greatly.