Power system transient stability enhancement by STATCOM with nonlinear H∞ stabilizer

A robust control design is presented for a single machine infinite bus system (SMIB) with a STATCOM. The controller for the nonlinear system is designed using the recently developed nonlinear H∞ theory. The approach combines state feedback exact linearization with linear H∞ principle, which avoids the difficulty of solving Hamilton-Jacoby-Issacs inequality. Simulation results with a number of disturbances like torque pulses and three-phase faults on the generator show that the proposed robust controller can ensure transient stability of the power system over a wide range of operating points