Blade pitch

About: Blade pitch is a research topic. Over the lifetime, 5321 publications have been published within this topic receiving 63134 citations.

Electrohydraulic propeller governor

Abstract: A propeller governor for controlling blade pitch of a variable pitch propeller has a hydraulic control circuit coupled to the propeller to change blade pitch in response to hydraulic pressure. The hydraulic control circuit has a first pressure path configured to adjust blade pitch within a first range of blade pitch, and a second, different pressure path configured to adjust blade pitch within a second range of blade pitch. An electrohydraulic servo valve of the governor is configured to adjust hydraulic pressure in the first pressure path to adjust blade pitch within the first range and to adjust hydraulic pressure in the second pressure path to adjust blade pitch within the second range.

Load measuring apparatus, method, and program

Abstract: A load is based calibrate on data collected under wide observation conditions and promptly calibrate loads of a plurality of wind turbine blades. A load measuring apparatus is applied to a wind turbine in which a pitch angle of a wind turbine blade is variable. The apparatus includes a sensor for obtaining a distortion of the wind turbine blade; a load calculating unit having a function expressing a relation between the distortion of the wind turbine blade and a load on the wind turbine blade, for obtaining the load on the wind turbine blade by applying to the function the distortion based on measurement data of the sensor; and a calibration unit for calibrating the function based on the measurement data of the sensor obtained in a pitch angle range and a rotational speed range of the wind turbine blade in which a variation between maximum and minimum aerodynamic torques is equal to or less than a predetermined value.

A wind turbine, a method for compensating for disparities in a wind turbine rotor blade pitch system and use of a method.

Abstract: The invention relates to a wind turbine comprising a rotor including one or more rotor blades, a pitch system for controlling the pitch angle of said one or more rotor blades, said pitch system comprises at least one pitch actuator, a pitch controller for generating pitch actuator control signals and sensor elements for establishing values of pitch performance parameters, and a compensation controller to compensate for disparities between said pitch actuator control signals and said values of pitch performance parameters, according to a control algorithm. The the compensation controller is arranged to adjust parameters of the control algorithm of said compensation controller in dependency of said disparities. Furthermore the invention relates to a method for compensating for disparities in a wind turbine rotor blade pitch system and use of a method.

Multivariate SCADA Data Analysis Methods for Real-World Wind Turbine Power Curve Monitoring

Abstract: Due to the stochastic nature of the source, wind turbines operate under non-stationary conditions and the extracted power depends non-trivially on ambient conditions and working parameters. It is therefore difficult to establish a normal behavior model for monitoring the performance of a wind turbine and the most employed approach is to be driven by data. The power curve of a wind turbine is the relation between the wind intensity and the extracted power and is widely employed for monitoring wind turbine performance. On the grounds of the above considerations, a recent trend regarding wind turbine power curve analysis consists of the incorporation of the main working parameters (as, for example, the rotor speed or the blade pitch) as input variables of a multivariate regression whose target is the power. In this study, a method for multivariate wind turbine power curve analysis is proposed: it is based on sequential features selection, which employs Support Vector Regression with Gaussian Kernel. One of the most innovative aspects of this study is that the set of possible covariates includes also minimum, maximum and standard deviation of the most important environmental and operational variables. Three test cases of practical interest are contemplated: a Senvion MM92, a Vestas V90 and a Vestas V117 wind turbines owned by the ENGIE Italia company. It is shown that the selection of the covariates depends remarkably on the wind turbine model and this aspect should therefore be taken in consideration in order to customize the data-driven monitoring of the power curve. The obtained error metrics are competitive and in general lower with respect to the state of the art in the literature. Furthermore, minimum, maximum and standard deviation of the main environmental and operation variables are abundantly selected by the feature selection algorithm: this result indicates that the richness of the measurement channels contained in wind turbine Supervisory Control And Data Acquisition (SCADA) data sets should be exploited for monitoring the performance as reliably as possible.

Rotor control with negative collective in high speed auto-rotation

Abstract: A method of operating a rotor aircraft at high speeds applies negative collective pitch to the rotor. The rotor aircraft has a wing, a thrust source and a rotor. During horizontal flight, the pilot operates the thrust source to move the aircraft forward. This supplies lift due to air flowing over the wing. By controlling tilt of the rotor, and without supplying power to the rotor, the pilot causes the rotor to auto-rotate due to the forward movement of the aircraft. The speed of rotation of the rotor is controlled by the degree of tilt of the rotor relative to the direction of flight. Once the aircraft speed is sufficiently high to cause reverse flow of air over the entire retreating blade of the rotor, the pilot reduces the collective pitch of the rotor to less than zero to reduce the flapping as desired.