The present invention relates to a method of determining an induction factor between the rotor plane (PR) and a measurement plane (PM), involving measuring the wind speed in at least two measurement planes (PM), determining the wind speed in rotor plane (PR) by use of a Kalman filter from the measurements, and measuring the induction factor by use of an adaptive Kalman filter from the measurements and the wind speed in rotor plane (PR).

A wind turbine including a rotor, a nacelle, a generator, and a wind sensor is provided, wherein the wind sensor is arranged above a part of the generator that extends between the rotor and the nacelle. Furthermore, a wind farm including a plurality of interconnected wind turbines is described. Yet further, a method of assembling or modifying a wind turbine is described.

A condition monitoring device for a wind turbine power generating apparatus provided with an auxiliary motor power supply system including a power-supply-side line connected to a power supply and a plurality of auxiliary-motor-side lines diverging from the power-supply-side line and connected to a plurality of auxiliary motors, respectively, comprises: a current measurement device for measuring a current flowing through the power-supply-side line; and a control device for controlling the plurality of auxiliary motors. The control device is configured to, when a generator of the wind turbine power generating apparatus is in a standby state where power generation is stopped at a low wind speed, execute a single sequential operation mode in which each of the plurality of auxiliary motors is singly and sequentially operated. The current measurement device is configured to measure a current flowing through the power-supply-side line during execution of the single sequential operation mode by the control device.

It is described a method of operating at least one adaptable airflow regulating system (13) of at least one rotor blade (15) of a wind turbine (1) connected to a utility grid (6), the method comprising: receiving information (10) regarding a grid disturbance; adapting, in particular during a disturbance duration, the airflow regulating system (13) based on the information (10), while the wind turbine (1) stays connected to the utility grid (6).

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.

A method for determining a yaw position offset of a wind turbine (1) is provided. A neighbouring wind turbine (2) of the wind farm is identified, the neighbouring wind turbine (2) being arranged in the vicinity of the wind turbine (1). Produced power data and/or wind speed data from the wind turbine (1) and from the neighbouring wind turbine (2), is obtained during a period of time, and a yaw position offset of the wind turbine (1) is derived, based on the obtained produced power data and/or wind speed data, and based on the geographical positions of the wind turbine (1) and the neighbouring wind turbine (2). A local maximum and a local minimum being separated by an angular difference in yaw position being substantially equal to 180°.

A wind turbine is disclosed which comprises a control system configured to execute at least one ice removal routine which comprises a heating stage of at least one of the blades (3), and a mechanical removal ice stage. A wind turbine removing ice method is also disclosed which comprises a stage wherein the presence of ice is detected on at least one of the blades and, once said presence of ice is detected, comprises a stage wherein at least one ice removal routine is activated which comprises, in turn, a heating stage of at least one of the blades and a mechanical removing ice stage on at least said blade.

A pitch control method and system of a symmetrical-airfoil vertical axis wind turbine collects data by an anemometer, an anemoscope and an angle sensor, outputs an optimum pitch angle based on a control law of a pitch angle and controls the pitch angle to be the optimum pitch angle through a pitch control actuator. In addition to input variables of the control law such as a wind velocity v.sub.in and a blade azimuth angle Ψ, constants such as a rotation radius R, a rotation velocity Ω of the blade and aerodynamic coefficients c.sub.1, c.sub.2 and c.sub.3 are also related. A Reynolds number has little influence on three aerodynamic coefficients c.sub.1, c.sub.2 and c.sub.3. The pitch actuator controls the adjustment rods to realize the automatic pitch control of the blades. An expression of the control law of the pitch is concise, the calculation time is short, and a response speed is fast.

The invention provides a method for controlling a wind turbine, including predicting behaviour of one or more wind turbine components such as a wind turbine tower over a prediction horizon using a wind turbine model that describes dynamics of the one or more wind turbine components or states. The method includes determining behavioural constraints associated with operation of the wind turbine, wherein the behavioural constraints are based on operational parameters of the wind turbine such as operating conditions, e.g. wind speed. The method includes using the predicted behaviour of the one or more wind turbine components in a cost function, and optimising the cost function subject to the determined behavioural constraints to determine at least one control output, such as blade pitch control or generator speed control, for controlling operation of the wind turbine.

A wind generator includes a revolving platform rotationally connected with a base; a tower body, where a bottom end of the tower body is connected to the revolving platform, a top end of the tower body is fixedly provided with a generator room, and a plurality of blades are rotationally connected to the generator room through a wheel hub; and the tower body is provided with at least one windward side in the circumferential direction of the tower body, and a bending stiffness of the windward side is not less than that of the remaining sides of the tower body; and a power source, where the power source is started when airflow is to the sides rather than the windward side to enable the airflow to flow to the windward side while the windward direction of the blades coincides with the airflow. A wind generator group is further provided.