Efficient simulation of wind generation systems using voltage-behind-reactance model of doubly-fed induction generators and average-value model of switching converters

Wind power generation has an essential role in renewable energy development. Doubly-fed induction generators (DFIGs) are widely used in wind energy systems due to their variable speed operation capability. In DFIG-based wind generation systems, the machine's stator is directly connected to the ac grid, while the rotor is controlled with a back-to-back converter. For practical simulation of large-scale wind farms, it is essential to have numerically efficient models for the electrical machines and converters. In this paper, a voltage-behind-reactance (VBR) model is presented for DFIGs. The new model achieves a direct interface of the machine's stator with external ac network, and can use the detailed and/or average-value-models (AVMs) of switching converters on the rotor. The proposed VBR model is demonstrated to achieve the best numerical efficiency and accuracy in all combinations of machine-converter models and outperforms the conventional qd model of DFIGs that typically requires interfacing snubber.