A method for identifying damage in a component of a wind turbine includes placing a conductive element onto at least one surface of the component of the wind turbine. The method also includes electrically connecting the conductive element into an electrical circuit. Further, the method includes monitoring a status of the electrical circuit to identify the damage in the component. In particular, when the status of the electrical circuit is open, damage is likely present in the component, and when the status of the electrical circuit is closed, damage is unlikely present in the component. Moreover, the method includes transmitting the status of the electrical circuit to a user interface for display.

The present disclosure is related to pitch systems for blades of wind turbines. The pitch system comprises a pitch bearing having a first bearing ring connected to a hub of the wind turbine, and a second bearing ring connected to a blade. The pitch system also includes an annular gear and a pitch drive having a motor, a gearbox, a main brake, and a pinion. In addition, the pitch system includes an auxiliary brake system comprising an auxiliary brake and an auxiliary pinion to engage with the annular gear, where the auxiliary brake is configured to switch between an active state, wherein braking forces are applied to the annular gear to maintain the blade in an instantaneous position, and an inactive state. The present disclosure further relates to wind turbines comprising such pitch systems and methods for applying an emergency pitch braking torque to a pitch system.

A method of operating a wind turbine in an active idle mode is provided, the wind turbine including a rotor hub with a plurality of blades which are configured to be pitched. The method including the following steps: detecting a fault of the wind turbine; determining a number of faulty blades, whose pitching operation is faulty or affected by a fault; and operating the wind turbine in the active idle mode based on the determined number of faulty blades.

The present disclosure is directed to a system comprising a structure being prone to lightning strikes and icing, wherein the structure comprises a shielding arrangement electrically connected to a lightning arrangement, an electric heating arrangement connected to a power source for mitigating icing of the structure, and an electrical insulation arrangement being effectively provided between the shielding arrangement and the electric heating arrangement. A power source is configured for applying a predetermined amount of electric test- and/or maintenance-energy such that the electric test- and/or maintenance-energy is effectively present between the shielding arrangement and the electric heating arrangement. A determination device is electrically connected to the shielding arrangement and to the electric heating arrangement in a way that the shield-heating-voltage and/or the shield-heating-current being present between the shielding arrangement and the electric heating arrangement can be determined.

The present disclosure relates to methods (100, 200) for estimating an actual value of an operational parameter (67) of a wind turbine (10). A method (100) comprises determining (120) which sensors of a plurality of sensors (61) of the wind turbine (10) are reliable and which sensors of the plurality of sensors (61) are unreliable. The method (100) further comprises estimating (130) the actual value of the operational parameter (67) based on a mathematical model and on data related to the operational parameter (63) measured by the reliable sensors.

Operating a renewable energy power includes receiving a measurement signal indicative of a measured power characteristic of the plant at a point of connection to a power network; controlling the plant 12) according to a normal mode of operation to provide power by determining and dispatching power set points, the power set points being determined by: acquiring samples of the measurement signal at a sample rate; and determining the power set points based on the sampled measurements and a target level for the measured power characteristic; and monitoring the measurement signal to detect an undersampled oscillation of the measured power characteristic in the sampled measurements, and thereby detecting a control fault; and then controlling the plant according to a fault mode of operation.

Operating a renewable energy power includes receiving a measurement signal indicative of a measured power characteristic of the plant at a point of connection to a power network; controlling the plant 12) according to a normal mode of operation to provide power by determining and dispatching power set points, the power set points being determined by: acquiring samples of the measurement signal at a sample rate; and determining the power set points based on the sampled measurements and a target level for the measured power characteristic; and monitoring the measurement signal to detect an undersampled oscillation of the measured power characteristic in the sampled measurements, and thereby detecting a control fault; and then controlling the plant according to a fault mode of operation.

A method for detecting and responding to a failure in a drivetrain of a wind turbine includes estimating a first rotational speed signal at a first location along the drivetrain via one or more rate gyroscopes mounted in a hub, the first rotational speed signal being a proxy for rotor speed of a rotor. The method also includes processing the first rotational speed signal to account for a bias in the first rotational speed signal due to use of the rate gyroscope(s). Further, the method includes receiving a second rotational speed signal at a second location along the drivetrain, the second location being downwind from the first location, the first and second locations being on opposing sides of a potential slip location of the drivetrain. Moreover, the method includes determining a speed error based on a comparison of the first and second rotational speed signals. In addition, the method includes comparing the speed error to a threshold and implementing a control action when the speed error exceeds the threshold.

Wind turbine cable connector monitoring method and device for monitoring a connector (1) attached to cable (4). A temperature sensor (6) is provided for sensing a measured temperature at a position a known distance along the cable (4) from the connector (1). A controller (8,19) records the measured temperature from the temperature sensor (6) while the connector (4) is in use, and identifies a potential fault condition in the connector (4) based on the measured temperature and the position the known distance along the cable (4) from the connector (1).

A wind turbine, a method and a control system for aligning a nacelle of a wind turbine with a target yaw angle is provided, wherein the control system includes a detection device configured for detecting at least one parameter indicative of wind forces acting on at least one component of the wind turbine for determining a current yaw angle of the nacelle, and an actuation device configured for manipulating a position of the nacelle until the current yaw angle is aligned with the target yaw angle, wherein the detection device includes at least one first bending moment sensor on a first component, wherein the detection device is configured for determining a bending moment of the first component based on data received from the first bending moment sensor as the at least one parameter indicative of wind forces acting on the at least one component of the wind turbine.