A detection method and detection apparatus for a wind driven generator, and a computer-readable storage medium, a computer device and a detection system for executing the method. The method comprises: acquiring corresponding operation data of a wind driven generator within a preset time period; according to the operation data, then determining comprehensive data corresponding to the wind driven generator, wherein the comprehensive data is used for reflecting a continuous operation state of the wind driven generator within the preset time period; and when the comprehensive data exceeds a first data threshold, generating first alarm information corresponding to the wind driven generator, wherein the first alarm information is used for indicating that the wind driven generator is in an abnormal operation state within the preset time period, the abnormal operation state may cause the increase of a fatigue load of a wind driven generator unit, thereby shortening the service life of the unit, the first data threshold is less than a second data threshold, and the second data threshold is used for determining whether the wind driven generator has a fault. In this method, in response to the comprehensive data exceeding the first data threshold, a wind driven generator processing device can generate the first alarm information corresponding to the wind driven generator, such that the problem of a unit being damaged because the wind driven generator operates in an unhealthy operation state can be avoided to a certain extent.

A method is for estimating health status of a pitch energy storage unit of a wind turbine. The method includes: providing an equivalent circuit model, ECM, of the storage unit, the ECM including an equivalent series resistor and an electrical energy storage element connected between two terminals; repeatedly sampling a voltage and a corresponding current at the two terminals; determining a voltage change and a current change for a plurality of voltage samples and corresponding current samples; performing an optimization procedure based at least on the ECM, the plurality of the voltage samples, the determined voltage changes, and the determined current changes to obtain an updated resistance of the equivalent series resistor and an updated model parameter of the storage element; and estimating a status of health parameter for the storage unit by comparing at least one of the updated resistance and the updated parameter with a threshold value.

A system and method are configured to monitor changes associated with an air gap in a brake assembly of a wind turbine yaw drive by: (1) receiving one or more sensor signals from one or more sensors that are indicative of changes associated with the air gap; and (2) comparing the changes associated with the air gap to certain thresholds to determine if the air gap is in need of attention. The system includes at least one proximity sensor arranged adjacent to the air gap, to monitor the air gap, and a controller. The controller is configured to receive the sensor signal(s) indicative of the changes associated with the air gap. The controller also is configured to compare the changes associated with the air gap to one or more air gap thresholds, and to implement a control action based on this comparison.

An online indirect measurement method for pitching and yawing moments of a wind or tidal current turbine is provided. The method uses an online indirect measurement system including an incoming flow velocity measurement module, a generator rotation speed measurement module, a pitch angle measurement module, and a computer; the incoming flow velocity measurement module measures the flow velocity of the rotor center; the generator rotation speed measurement module measures the generator rotation speed; the pitch angle measurement module measures the pitch angle of each blade; the computer receives signals of flow velocity, generator rotation speed, and pitch angle, obtains the pitching moment and yawing moments of the turbine via an online calculation, and displays and stores the measured and calculated data in real time.

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.

A method of calibrating a yaw actuator of a wind turbine is provided, including steps of performing an active yaw operation in a clockwise yaw direction and an active yaw operation in a counter-clockwise yaw direction; recording data of a wind direction and a power caused by both yaw operations, and averaging the data and calculating an error between an experimental power difference and a theoretical power difference of yaw operations in the clockwise direction and a counter-clockwise direction; determining a minimum of the error; and determining a yaw misalignment based on the minimum error.

A turbofan engine for an aircraft includes a fan and a fan actuation system. The fan has a plurality of fan blades coupled to a fan shaft having one or more fan bearings. The fan blades are rotatable about a pitch axis. The fan actuation system is disposed within a fan hub and includes one or more actuators for rotating the fan blades about the pitch axis and one or more radial thrust bearings. The fan actuation system is characterized by a fan actuation system length envelope in a range of 8.5 to 24 and given by

[00001]$\frac{N_{\mathrm{FB}}{D}_{\mathrm{FT}}}{L_{\mathrm{AXIAL}}\left(\frac{R_{\mathrm{TB}}}{N_{\mathrm{FB}}}\right)}.$

N.sub.FB is a number of the fan blades, D.sub.FT is a fan tip diameter of the fan blades, R.sub.TB is a thrust bearing radius of the radial thrust bearings, and L.sub.AXIAL is an axial length from a fan hub tip to the fan bearings.

The invention relates to a method for monitoring yawing fault events of a yaw system of a wind turbine. The yaw system comprises one or more actuators for driving the yaw system and a holding system to resist yaw rotation. The yaw system is arranged to provide yaw rotation in response to a yaw control signal. According to the method, the monitored yaw angle is compared with the yaw control signal, and based on the comparison, a correlation between a monitored change in the yaw angle and the yaw control signal is determined. A yawing fault event is determined dependent on the determined correlation.

A system and method operate a wind farm having a plurality of wind turbines, and include determining a wind direction of a wind affecting the wind farm. Based on the wind direction, at least one upwind turbine is identified that produces a wake effect on one or more downwind wind turbines, the upwind wind turbine and affected downwind wind turbines defining a cluster. Based on a current yaw position of the upwind turbine and the wind direction, a yaw steer is determined for the upwind turbine to reduce the wake effect on the downstream wind turbines in the cluster. The yaw steer is based on increasing a net energy gain from the cluster, the net energy gain determined by subtracting an energy cost of the yaw steer from an increased energy production of the cluster resulting from the yaw steer. The upwind wind turbine is controlled to change yaw position in accordance with the yaw steer when the net energy gain satisfies a minimum threshold level.