Low voltage ride‐through capability enhancement of grid‐connected permanent magnet synchronous generator driven directly by variable speed wind turbine: a review

The large power penetration of wind farms into the power grids requires new regulations by transmission system operators to keep them connected to the grid as long as possible. Grid disturbances such as voltage dips cause islanding of wind farms on the way to protect its apparatus from damage due to a high current flowing. The grid stability will suffer due to the islanding of large‐scale wind farms. Wind farms should keep on connecting to the grid during low voltages for a specific time [low voltage ride through (LVRT) capability] to support the grid stability restoring. LVRT capability of permanent magnet synchronous generator driven directly by a variable speed wind turbine (PMSG‐VSWT) can be realised by modifying the control of grid side converter (GSC), machine side converter (MSC), pitch angle control, or using the existing energy storage system. This study presents a review of recent proposed improvements to enhance the LVRT capability of PMSG‐VSWT. Many artificial intelligence and conventional controllers are used to enhance the control performance during voltage sags to keep the wind farms connected to the grid according to the recent grid codes.