Abstract:
Die vorliegende Erfindung betrifft Verstell- und/oder Antriebseinheiten wie sie bei Windkraftanlagen zum Einstellen des Azimut-Winkels der Windkraftanlagengondel oder des Pitch-Winkels der Rotorblätter eingesetzt werden können, wobei eine solche Verstell- und/oder Antriebseinheit zumindest zwei Stellantriebe zum Verdrehen zweier zueinander verdrehbar gelagerter Baugruppen sowie eine Steuereinrichtung zum Ansteuern der Stellantriebe aufweist, die die Stellantriebe derart ansteuert, dass die Stellantriebe beim Verdrehen der beiden Baugruppen und/oder im Stillstand der Baugruppen zueinander verspannt werden. Die Erfindung betrifft ferner eine Windkraftanlage mit einer solchen Verstell- und/oder Antriebseinheit sowie ein Verfahren zum Steuern einer solchen Verstell- und/oder Antriebseinheit. Erfindungsgemäß umfasst die Steuereinrichtung eine Verspannungs-Einstelleinrichtung zum variablen Einstellen der Stärke der Verspannung der Stellantriebe in Abhängigkeit einer variablen äußeren Last auf die zu verstellenden Baugruppen, die mittels einer Lastbestimmungseinrichtung bestimmbar ist. Nach einem weiteren Aspekt der Erfindung ist ein Überlastschutz vorgesehen, wobei durch Belastungs-Bestimmungseinrichtungen die individuellen Lasten der einzelnen Stellantriebe bestimmt und bei Erreichen einer Überlastung eines Stellantriebs die Verteilung der Antriebsmomente verändert wird derart, dass der in die Überlastung kommende Stellantrieb entlastet oder zumindest nicht weiter belastet wird und zumindest ein weiterer Stellantrieb stärker unterstützend belastet oder weniger verspannend belastet wird.
Abstract:
The present invention relates to a method and wind turbine for determining a dynamic twist of one or more blades. One or more first signals are received from a first wireless sensor attached to a blade of a wind turbine and a first angle is determined based on the received first signals. One or more second signals are received from a second wireless sensor attached to a blade of a wind turbine and spaced apart from the first wireless sensor by a predetermined distance. A second angle is determined based on the received second signals. A dynamic twist of the blade is determined based on the determined first angle, the determined second angle and the predetermined distance.
Abstract:
The present invention provides a method of operating a wind turbine. The wind turbine comprises at least one rotatable blade. The method comprises the steps of providing a load sensor configured to generate a load signal representing loading on the blade, generating a first load signal when the blade is in a first position, and generating a second load signal when the blade is in a second position. Additionally, the method comprises steps of detecting a rotational speed of the blade, calculating a weight force on the blade based on the first and the second load signal, and calculating a centrifugal force on the blade based on the first and the second load signal. Subsequently, the weight force is compared with a predetermined weight force, and the centrifugal force is compared with a predetermined centrifugal force at the detected rotational speed. Finally, a risk of ice throw is determined based on the comparisons of the weight force and the centrifugal force with the predetermined forces.
Abstract:
A method and system for improving the balance of a rotor in a wind turbine, including; determining blade load data associated with a selected rotor blade pair; determining, based on the blade load data, pitch imbalance data associated with the selected rotor blade pair, wherein the pitch imbalance data associated with a rotor blade pair is based on measurements of at least blade loading, rotor speed and wind speed; and, determining and applying pitch control inputs to one or both of the selected rotor blade pair in order to reduce the severity of the rotor imbalance.
Abstract:
The present invention provides a hydroelectric turbine system (10) including a base (12) on which a hydroelectric turbine (14) is mounted and supported, the base (12) having a number of fixed length legs (20) and at least one adjustable length leg (22), in order to allow all of the legs to contact the seabed in order to evenly distribute the system load into the seabed.
Abstract:
Method of operating a wind turbine comprising a plurality of blades rotatable along their longitudinal axes using a pitch mechanism, and comprising one or more movable trailing edge surfaces. The method includes predicting,at a first moment in time,a high load for one or more of the blades at a second moment in time. The method further comprises actuating on one or more of the movable trailing edge surfaces of these blades such that the trailing edge surfaces have a wider range of control to counteract the predicted high loads before the second moment in time, and simultaneously pitching the blades such as not to negatively affect the operation of the wind turbine. The method furthermore comprises,at the second moment in time, actuating the one or more movable trailing edge surfaces of the at least one or more blades to counteract the high loads.
Abstract:
The invention relates to a method of controlling a wind turbine comprising one or more blades attached to a rotor hub, the one or more blades being arranged to pitch relative to the hub, the method comprising the steps of obtaining a blade load signal comprising data on an absolute load on the one or more blades; processing the blade load data to detect a high thrust wind event, and generating a control signal comprising a pitch contribution for affecting the blades to pitch out of the wind in response to the detected wind event. The invention also relates to a wind turbine, a control system for a wind turbine and a computer program product being adapted to enable a computer system to perform the method of the invention.
Abstract:
A wind turbine having a hub (210) rotably attached to a nacelle (200), at least two blades (1, 2, 3) rotationally attach to the hub (210) to allow a change in blade pitch angle (T-?, T2 T3) a blade-pitch system (250) for individually controlling the blade-pitch angle (T?, 02 T3) of each blade, a supervisory control unit for issuing a first pitching command, a rotor position sensor (238) generating a rotor-position signal (ß) indicative of the rotor azimuthally position, a rotor-rotational-rate sensor (236) generating a rotor-rotational-rate signal (O) indicative of the rotor rotational speed, and a tower (100) supporting the nacelle (200), comprising a nautical-pitch-rate sensor (230) generating a nautical-pitch-rate signal (?) indicative of the nautical-pitch-rate of the wind turbine and a computational unit (240, 241) receiving turbine-state signals comprising the rotor-position signal (ß), the rotor-rotational-rate signal (O), and the nautical-pitch-rate signal (?).
Abstract:
Method and blade monitoring system for monitoring bending moment of a wind turbine blade (10). The method comprises obtaining a first sensor set signal indicative of a first bending moment at a first sensor position different from the tip (14) end along the longitudinal axis of the wind turbine blade, and estimating a bending moment at a first estimation position along the longitudinal axis based on the first sensor set signal, wherein the first sensor position is different from the first estimation position along the longitudinal axis. The blade monitoring system comprises a processing unit and an interface connected to the processing unit, the processing unit being configured for performing the method.
Abstract:
A method for wind gust detection and classification in a wind turbine. The wind turbine includes a tower and a rotor provided with a number of rotor blades on a rotor axis. The rotor is arranged on the tower. The method includes a) collecting data of a mechanical loading condition of the wind turbine, the data being associated with at least two loads exerted on the construction of the wind turbine; b) converting the data to the associated loads e in a non-rotating reference frame; c) monitoring temporal evolutions of the loads, comprising: c1) determining steady state components of the loads; c2) obtaining residuals of the loads by removing the respective steady state component from the loads; d) detecting by a test condition if the temporal evolutions of the residuals indicate that a wind gust is evolving; e) classifying the wind gust in one of a plurality of predetermined wind gust classes based on predetermined characteristics for the temporal evolutions of the residuals of the loads; f) based on the result of the classification, generating signals for adjusting the operation of the wind turbine.