Variable Rated Speed Control in Partial Load Operation of a Wind Turbine

A system for operating a wind turbine during partial load operation, the system comprising:

• a controller comprising one or more processors, the one or more processors configured to perform one or more operations, the one or more operations comprising:
• providing a rated power for the wind turbine;
• comparing a power output of the wind turbine with the rated power;
• if the power output is at the rated power, maintaining a speed set point of the wind turbine equal to a rated speed set point;
• and,
• if the power output is below the rated power, varying the speed of the wind turbine based on a non-monotonic torque-speed relationship.

A method for operating a wind turbine during partial load operation, the method comprising:

• providing a rated power for the wind turbine;
• if a power output of the wind turbine is at the rated power, maintaining a speed of the wind turbine equal to a rated speed set point;
• and,
• if the power output is below the rated power, operating the speed of the wind turbine based on a non-monotonic torque-speed relationship and system constraints of the wind turbine.