Operating a wind turbine generator during an abnormal grid event

A computer program product directly loadable into the internal memory of at least one digital computer, said computer program product comprising software code portions for carrying out an operation for controlling an amount of power to be delivered from a wind turbine generator to a power grid during an abnormal power grid event when said computer program product is run on the at least one digital computer, the operation comprising:

• responsive to detecting the abnormal power grid event, transitioning control of the wind turbine generator from a power mode to a current mode;
• and
• within the current mode:
• controlling, using a first closed control loop, an active current delivered to the power grid in response to a determined total active current;
• and
• controlling, using a second closed control loop, a reactive current delivered to the power grid in response to a determined total reactive current,
• wherein one or both of the first closed control loop and the second closed control loop respectively comprises:
• an outer closed control loop comprising a current regulator;
• and
• an inner closed control loop comprising a current rotor controller,
• wherein the current regulator provides at least a portion of a control signal to the current rotor controller.

A wind turbine generator comprising:

• a power controller configured to control an amount of power to be delivered to a power grid during an abnormal power grid event, the power controller comprising:
• a detector configured to detect the abnormal power grid event, wherein the power controller is configured to transition from a power mode to a current mode responsive to detecting the abnormal power grid event;
• a first closed control loop configured to control, in the current mode, an active current delivered to the power grid;
• and
• a second closed control loop configured to control, in the current mode, a reactive current delivered to the power grid,
• wherein one or both of the first closed control loop and the second closed control loop respectively comprises:
• an outer closed control loop comprising a current regulator;
• and
• an inner closed control loop comprising a current rotor controller,
• wherein the current regulator provides at least a portion of a control signal to the current rotor controller.