Wind farms in weak grids enhancement of ride-through capability using Custom Power Systems

In the last years, the wind power generation incorporated into the standard grid has been increased significantly. This situation forced the revision of the electric utilities grid codes requirements, to guarantee the reliability in systems with high wind energy penetration. Particularly in transient conditions, the wind farms must withstand several types of disturbances coming from the grid, such as voltage sags, swells, unbalances, etc., keeping the connection to the system to avoid power imbalance and collapse. In this work is analyzed the behavior of a wind farm with squirrel cage induction generators connected to a weak grid, facing three-phase voltage sag, and are proposed compensation strategies to improve the wind farm stability using custom power systems devices (CUPS). The obtained results show the validity of the proposed strategies based on the use of CUPS devices, and the particular advantage of the series compensation with active power injection.