Doubly-fed induction machine models for stability assessment of wind farms

The increasing size of wind farms requires power system stability analysis including dynamic models of the wind power generation. Nowadays, the most widely used generator type for units above 1 MW is the doubly-fed induction machine. Doubly-fed induction machines allow active and reactive power control through a rotor-side converter, while the stator is directly connected to the grid. Detailed models for doubly-fed induction machines are well known but the efficient simulation of entire power systems with hundreds of generators requires reduced order models. This paper presents a fundamental frequency doubly-fed induction machine model including a typical control system and discusses the accuracy of reduced order models under various operating conditions.