Abstract: Systems, methods, and computer program products for controlling a yaw system of a wind turbine. The yaw system includes mechanical brakes that provide a first amount of braking torque when closed. The yaw system is configured to transition from a yawing state to a parked by brake state by closing mechanical brakes in a first subset of the mechanical brakes and opening each mechanical brake in a second subset of the mechanical brakes. The second subset provides a second amount of braking torque that is less than the first amount of braking torque. In response to detecting a rotation of the nacelle while in the parked by brake state, the yaw system is configured to transition from the parked by brake state to a parked by motor state in which yaw drives are activated to provide a counter acting torque in opposition to the detected rotation of the nacelle.

Abstract: Techniques for controlling the yaw of a wind turbine system by controlling a plurality of yaw drive actuators. When the yaw drive actuators are applying the same torque to all the motors, this can lead to some motors overspeeding, if the motor is not engaged when the yaw system is activated. Therefore, if the actual motor speed reference of a yaw drive actuator is higher than a specific motor speed reference, then an output signal to reduce the actual motor speed reference is applied to the yaw drive actuators with an actual motor speed reference higher than the specific motor speed reference.

Abstract: Techniques for controlling the yaw of a wind turbine system by controlling a plurality of yaw drive actuators. When the yaw drive actuators are applying the same torque to all the motors, this can lead to some motors overspeeding, if the motor is not engaged when the yaw system is activated. Therefore, if the actual motor speed reference of a yaw drive actuator is higher than a specific motor speed reference, then an output signal to reduce the actual motor speed reference is applied to the yaw drive actuators with an actual motor speed reference higher than the specific motor speed reference.

Abstract: Techniques for controlling the yaw of a wind turbine system by controlling a plurality of yaw drive actuators. Based on a requested motor speed reference as an input signal, and a mean motor speed reference as a feedback signal, the method determines a required motor torque reference as an output signal for the plurality of yaw drive actuators. The plurality of yaw drive actuators rotates a nacelle or a structure comprising a plurality of nacelles such that an even load distribution is provided for the plurality of yaw drive actuators.