Nonlinear disturbance attenuation control for STATCOM

In this paper, the nonlinear robust control approach is adopted to static synchronous compensator (STATCOM) control. Based on the power system dynamics, the framework of dissipative system theory and the approach of nonlinear disturbance attenuation in the sense of L₂ -gain, the robust control dynamic model of STATCOM in a one-machine, infinite-bus system has been established. The torque disturbance acting on rotating shaft of the generator set and the disturbance to output voltage of STATCOM are considered in the model. A recursive approach is applied to construct the energy storage function of the system such that the solution of the control problem is acquired, which avoids the difficulty from solving Hamilton-Jacobi-Isaacs inequality. Thus, the nonlinear disturbance attenuation control strategy of STATCOM is obtained. The simulation results demonstrate that STATCOM with the proposed controller can more effectively improve the voltage stability, damp the oscillation, and enhance the transient stability of power systems