Controlling a wind turbine during a low voltage grid event using MPC

A control system for a wind turbine, comprising:

• a controller unit arranged for detecting a low voltage event where a grid voltage drops from a first level and to a second lower level;
• a controller unit arranged for operating the wind turbine during the low voltage event in a grid event mode;
• a controller unit arranged for detecting a termination of the low voltage event;
• a controller unit arranged for operating the wind turbine in a recovery mode, wherein the controller unit is arranged for receiving a current operational state of the wind turbine and receive or determine a post-event operational state;
• a controller unit arranged for, based on the current operational state and the post-event operational state, calculating one or more predicted operational trajectories using a MPC routine with a maximal time to reach the post-event operational state as a constraint, the one or more predicted operational trajectories including a predicted control trajectory, where a trajectory comprises a time series of at least one variable;
• and
• a controller unit capable of generating instructions for controlling the wind turbine based on the control trajectory.

A wind turbine, comprising

• a tower;
• a nacelle disposed in the tower;
• a rotor extending from the nacelle and having a plurality of blades disposed on a distal end thereof;
• a control system configured to perform an operation, comprising:
• detecting a low voltage event where a grid voltage drops from a first level and to a second lower level;
• operating the wind turbine during the low voltage event in a grid event mode;
• detecting a termination of the low voltage event;
• receiving a current operational state of the wind turbine;
• receiving or determining a post-event operational state;
• based on the current operational state and the post-event operational state, calculating one or more predicted operational trajectories using a MPC routine with a maximal time to reach the post-event operational state as a constraint, the one or more predicted operational trajectories including a predicted control trajectory, where a trajectory comprises a time series of at least one variable;
• and
• controlling the wind turbine using the control trajectory.