Abstract: A wind turbine system (20, 70) is connected to an electrical grid (42) by an inverter (38) that provides turbine terminal voltage (Vt) support to the grid during a grid low voltage fault that is concurrent with a lack of real power production from the generator (30) by providing reactive power to the grid. A processor (46) controls the inverter to preserve a minimum voltage on a local DC bus (34) by stopping the reactive power output when the DC bus voltage drops to a threshold value (59) that is above a low bus voltage trip setpoint (56). An energy storage device (48) such as a battery may be connected to the DC bus to provide power that supports a prolonged ride-through capability during the grid fault.

Abstract: A wind turbine system (20, 70) is connected to an electrical grid (42) by an inverter (38) that provides turbine terminal voltage (Vt) support to the grid during a grid low voltage fault that is concurrent with a lack of real power production from the generator (30) by providing reactive power to the grid. A processor (46) controls the inverter to preserve a minimum voltage on a local DC bus (34) by stopping the reactive power output when the DC bus voltage drops to a threshold value (59) that is above a low bus voltage trip setpoint (56). An energy storage device (48) such as a battery may be connected to the DC bus to provide power that supports a prolonged ride-through capability during the grid fault.

Abstract: A wind farm (10) may include a plurality of variable speed wind turbines (12, 14, 16). A centralized controller (50) may be configured to selectively adjust a respective electrical output power from each of the wind turbines at least during an underfrequency condition. The controller may include a monitor (52) configured to monitor a grid frequency value relative to at least a first threshold value. A deviation of the grid frequency value beyond the first threshold value is indicative of the underfrequency condition. The controller further includes a control unit (54) configured to effect a step response to the electrical output power of the wind turbine in a direction selected to counteract the underfrequency condition.

Abstract: A wind farm (10) may include a plurality of variable speed wind turbines (12, 14, 16). A centralized controller (50) may be configured to selectively adjust a respective electrical output power from each of the wind turbines at least during an underfrequency condition. The controller may include a monitor (52) configured to monitor a grid frequency value relative to at least a first threshold value. A deviation of the grid frequency value beyond the first threshold value is indicative of the underfrequency condition. The controller further includes a control unit (54) configured to effect a step response to the electrical output power of the wind turbine in a direction selected to counteract the underfrequency condition.