The Inertial Response of Induction-Machine-Based Wind Turbines

The inertial response of a generator is influenced by the sensitivity of the generator´s electromagnetic torque to changes in the power system frequency. This paper deals with the inertial response of wind turbines employing induction-machine-based generators. A model of a field-oriented controlled doubly fed induction generator based on a fifth-order induction-generator model is described. The proposed model is implemented in a reference frame that allows the factors affecting the inertial response of a doubly fed induction generator to be easily examined. A comparison between the inertial response of a squirrel-cage and doubly fed induction-machine-based wind-turbine generator is performed using the developed models. It is found that the inertial response of a doubly fed induction generator employing field-oriented control is strongly influenced by the rotor current-controller bandwidth.