Impact of Backlash Nonlinearity on the Dynamics of Type-3 Turbine-based Windfarms

This paper considers detailed modeling of gear backlash in the drivetrains of a type-3 turbine-based windfarm in an interconnected power system. The detailed model has been used to: (a) thoroughly investigate the impact of backlash on the dynamic performance and response of the windfarm; (b) identify the nature of various modes and the change of the modal properties with changes in system parameters and operating conditions through eigenvalue analysis; and (c) study the effect of traditional lead-lag and linear quadratic stabilizers on oscillation suppression, particularly blade vibrations. Novel indices and realistic wind speed profile simulated using Van'der Hoven spectrum have been used to study the impact of backlash and variation in its width on the dynamic performance of the wind farm. Also, inadequacies in existing models of type-3 turbines have been identified in terms of control design.