Abstract: A method, system and computer program product for operating a wind turbine is disclosed. For operating the wind turbine a set of operational data points are sensed via a sensing module. The set of operational data points may include bending stress values. Based on the bending stress values, a load scenario indicator value may be computed. Further, based on the set of operational data points a loading threshold value may be obtained. At least one operating parameter of the wind turbine is changed if the load scenario indicator value exceeds the loading threshold.

Abstract: A system for determining wind turbine tower base torque loads including a controller configured to determine a torque load of a base of a tower of a wind turbine according to a computation of an effective height of the wind turbine multiplied by a wind force upon a rotor of the wind turbine, and generate a control signal representing the torque load. A method for determining wind turbine tower base torque loads including determining a torque load of a base of a tower of a wind turbine according to the foregoing computation, and generating a control signal representing the torque load.

Abstract: A system and method for reducing rotor loads in a wind turbine that includes a brake and one or more rotor blades coupled to a rotor. Upon detection of a loss of counter torque and a blade-pitch failure in at least one rotor blade, a processor reduces a generator overspeed threshold value by a predetermined amount and determines a brake-release threshold value. The brake is applied to slow the rotor if the generator/rotor speed exceeds the reduced generator/rotor overspeed threshold value. In addition, the brake is applied to slow the rotor until the generator/rotor speed is below the brake-release threshold value. The rate of change of the pitch angle of the rotor blade may be varied as the blade moves toward feather in response to the detected blade-pitch failure.

Abstract: A wind turbine includes a plurality of wind turbine blades attached to a rotor positioned atop a tower affixed to a tower foundation. At least one blade pitch sensor is configured to measure blade pitch angles for one or more of the wind turbine blades. A rotor/generator speed sensor is configured to measure the rotational speed of the wind turbine rotor, a corresponding wind turbine generator, or both. A wind turbine nacelle yaw sensor is configured to measure the nacelle yaw, while at least two tower-base bending sensors are configured without use of adhesives, cements or bonding agents to provide large-area measurement of tower deflection. A controller is configured to adjust the pitch angle of one or more of the wind turbine blades in response to the measured one or more blade pitch angles, the measured rotational speed, the measured nacelle yaw and measured tower longitudinal deflection.

Abstract: A wind turbine includes a plurality of wind turbine blades attached to a rotor positioned atop a tower affixed to a tower foundation. At least one blade pitch sensor is configured to measure blade pitch angles for one or more of the wind turbine blades. A rotor/generator speed sensor is configured to measure the rotational speed of the wind turbine rotor, a corresponding wind turbine generator, or both. A wind turbine nacelle yaw sensor is configured to measure the nacelle yaw, while at least two tower-base bending sensors are configured without use of adhesives, cements or bonding agents to provide large-area measurement of tower deflection. A controller is configured to adjust the pitch angle of one or more of the wind turbine blades in response to the measured one or more blade pitch angles, the measured rotational speed, the measured nacelle yaw and measured tower longitudinal deflection.

Abstract: An apparatus and method for controlling a wind turbine having a plurality of blades such that the blade angle of each blade is continuously adjusted during loss of grid power relative to a wind direction relative to an orientation of the nacelle (i.e., yaw offset) and a rotor azimuth while keeping the orientation of the nacelle of the wind turbine substantially constant. The wind turbine is capable of pitching the blades a full 360 degrees and generating power from the rotation of the rotor shaft during loss of grid power.

Abstract: An apparatus and method for controlling a wind turbine having a plurality of blades such that the blade angle of each blade is continuously adjusted during loss of grid power relative to a wind direction relative to an orientation of the nacelle (i.e., yaw offset) and a rotor azimuth while keeping the orientation of the nacelle of the wind turbine substantially constant. The wind turbine is capable of pitching the blades a full 360 degrees and generating power from the rotation of the rotor shaft during loss of grid power.

Abstract: A system for determining wind turbine tower base torque loads including a controller configured to determine a torque load of a base of a tower of a wind turbine according to a computation of an effective height of the wind turbine multiplied by a wind force upon a rotor of the wind turbine, and generate a control signal representing the torque load. A method for determining wind turbine tower base torque loads including determining a torque load of a base of a tower of a wind turbine according to the foregoing computation, and generating a control signal representing the torque load.

Abstract: A system and method for reducing rotor loads in a wind turbine that includes a brake and one or more rotor blades coupled to a rotor. Upon detection of a loss of counter torque and a blade-pitch failure in at least one rotor blade, a processor reduces a generator overspeed threshold value by a predetermined amount and determines a brake-release threshold value. The brake is applied to slow the rotor if the generator/rotor speed exceeds the reduced generator/rotor overspeed threshold value. In addition, the brake is applied to slow the rotor until the generator/rotor speed is below the brake-release threshold value. The rate of change of the pitch angle of the rotor blade may be varied as the blade moves toward feather in response to the detected blade-pitch failure.

Abstract: An apparatus and method for extending the power-capture region of a wind turbine during certain operating conditions is disclosed. The actual set point of an operational parameter is selected so as to be maintained at a predetermined number of standard deviations away from an operating limit during certain operating conditions. For example, the operational parameter may be a rotor/generator speed and the operating condition may be a mean wind speed that exceeds a predetermined wind speed.

Abstract: An apparatus and method for reducing asymmetric rotor load in a wind turbine includes calculating a time delay for pitching each blade toward feather upon initiation of a shutdown condition. The blades with the larger blade angle begin moving toward feather with an initial pitch rate, while the blade with the smallest blade angle begins moving toward feather with a final pitch rate. Once all the blades have reached approximately an identical blade angle, the blades move simultaneously together to feather at the final pitch rate. By introducing the time delay for pitching the blades having higher blade angles at the final pitch rate, a simple, time-based correction of initial conditions during shutdown reduces the extreme loads on turbine components.

Abstract: An apparatus and method for extending the power-capture region of a wind turbine during certain operating conditions is disclosed. The actual set point of an operational parameter is selected so as to be maintained at a predetermined number of standard deviations away from an operating limit during certain operating conditions. For example, the operational parameter may be a rotor/generator speed and the operating condition may be a mean wind speed that exceeds a predetermined wind speed.

Abstract: A method for braking a wind turbine including at least one rotor blade coupled to a rotor. The method includes selectively controlling an angle of pitch of the at least one rotor blade with respect to a wind direction based on a design parameter of a component of the wind turbine to facilitate reducing a force induced into the wind turbine component as a result of braking.