A method and an apparatus for controlling noise of multiple wind turbines. The method includes: determining a noise-influencing sector of each of the multiple wind turbines, based on positions of the multiple wind turbines and a position of a noise-influencing site; acquiring a current wind direction; determining whether there is at least one wind turbine of the multiple wind turbine under the current wind direction operating in the noise-influencing sector; and limiting output power of the at least one wind turbine, in a case that the determination is positive.

The present invention provides a hydraulic turbine cavitation acoustic signal identification method based on big data machine learning. According to the method, time sequence clustering based on multiple operating conditions under the multi-output condition of the hydraulic turbine set is performed by utilizing an neural network, characteristic quantities of the hydraulic turbine set under a steady condition in a healthy state is screened; a random forest algorithm is introduced to perform feature screening of multiple measuring points under steady-state operation of the hydraulic turbine set, optimal feature measuring points and optimal feature subsets are extracted, finally a health state prediction model is constructed by using gated recurrent units; whether incipient cavitation is present in the equipment is judged. The present invention can effectively identify the occurrence of incipient cavitation in the hydraulic turbine set, reducing unnecessary shutdown of the equipment and prolonging the service life.

Provided is a method for controlling a wind turbine, in particular an electric generator of said wind turbine. The method includes an optimization during which a suitable operating parameter for controlling said wind turbine or generator thereof is determined, in particular in an iterative manner. The optimization includes providing a multidimensional space comprising a plurality of parameters; providing an objective function for said multidimensional space, e.g., a simplex has a shape of a triangle or a tetrahedron; and determining one parameter of said multidimensional space as a suitable operating parameter by applying said objective function to said multidimensional space, in particular in an iterative manner. The method includes selecting a suitable operating parameter as an operating parameter for said wind turbine or generator thereof; and operating said wind turbine or generator based on said operating parameter, in particular by controlling a converter connected to said generator.

A system and method of monitoring a tubular structure is provided. The method includes: a) sensing one or more parameters relating to the tubular structure at spaced apart positions along the length of the tubular structure using a sensor module array having a plurality of sensor modules disposed in a cable attached to the tubular structure, the plurality of sensor modules producing communication signals representative of the sensed parameter at each position along the length of the tubular structure; and b) using a control unit to communicate with the sensor modules in the array, including receiving communication signals representative of the sensed parameter at each position along the length of the tubular structure, and processing the communications signals to produce information relating to the sensed parameter at the positions along the length of the tubular structure.

A rotor blade with a leading edge and a trailing edge is provided, wherein the rotor blade is for being exposed to a fluid flowing substantially from the leading edge to the trailing edge, the rotor blade includes at least three sensors designed for detecting flow characteristics of the fluid and providing respective sensor signals, wherein the sensors are arranged with a non-uniform spacing, and the rotor blade further includes at least one actuator for producing an anti-noise signal based on a sensor signal, the sensors and the actuator are arranged at the surface of the rotor blade, and the actuator is arranged and prepared such that flow-induced edge noise of the rotor blade, which is generated by the fluid, is at least partly cancelled out by the anti-noise signal. A method for creating such rotor blade and a related wind turbine is also provided.

Provided is a method for controlling an electric generator of a wind turbine. The method includes varying an amplitude and/or phase angle of an harmonic current of said electric generator, while said electric generator is rotating, in particular at a known condition, measuring a signal indicative of generator vibration after and/or during varying said amplitude and/or phase angle, repeating said varying and said measuring until a predetermined requirement is met, evaluating an operating point for said electric generator by using said measured signals indicative of generator vibration in order to reduce a ripple torque of said generator, and controlling a current, in particular said harmonic current, of said electric generator in order to meet said operating point.

A method and apparatus for inspecting a wind turbine blade. The method includes: acquiring a sound signal generated by an impingement of wind on the wind turbine blade using a sound acquisition device; generating a frequency spectrogram corresponding to the sound signal; and obtaining a damage recognition result of the wind turbine blade from the frequency spectrogram by performing image recognition on the frequency spectrogram based on a damage recognition model. With the method, a damage type of the wind turbine blade is accurately recognized based on the frequency spectrogram without manual inspection. Therefore, human resources are saved. In addition, the health state of the wind turbine blade can be monitored in real time.

A method and an apparatus for controlling noise of a wind turbine. The method includes: determining a noise-influencing sector of the wind turbine based on a position of the wind turbine and a position of a noise-influencing site; acquiring a current wind direction; determining whether the wind turbine under the current wind direction operates in the noise-influencing sector; and limiting output power of the wind turbine, and increasing, after the wind turbine goes out from the noise-influencing sector and the output power reaches a rated power, the output power, in a case that the determination is positive.

Methods and related apparatus for improving synchronization of two or more engines on an aircraft are disclosed. Such method may be used where each engine comprises a first spool and a second spool, and, where a rotational speed of a first spool of a first engine has been substantially synchronized with a rotational speed of a first spool of a second engine. An exemplary method comprises receiving a value of a sensed parameter useful in controlling the first engine; adding a bias to the value; and using the biased value for controlling the first engine to cause a change in rotational speed of the second spool of the first engine in relation to the rotational speed of the first spool of the first engine.

A method of controlling a wind turbine, wherein the wind turbine includes a hub having at least one blade with at least one an add-on member which is actuated to alter aerodynamic properties of the blade. The method includes a step of acquiring a target noise level, and a step of controlling the at least one add-on member of the blade such that an actual noise level caused by the operation of the wind turbine is equal to or below the target noise level.