Abstract: A ventilation device, in particular for heating, cooling and/or humidifying air in residential buildings, includes a duct-shaped housing (1) with an air inlet opening (2) and an air outlet opening (3), and a fan impeller (6) as well as a filter unit, heat exchange unit and/or heating coil unit (14) arranged in the main flow direction (Z) of an air flow generated by the fan impeller (6). An air guiding device (17) is arranged in the flow direction (Z) of the air flow in front of a suction nozzle (16)—configured as a flow conditioner, includes a bar structure with air guiding bars-such that a flow inlet opening is configured on the suction side at an axial height in front of the flow inlet opening (15) by the bar structure whose opening surface is smaller than the opening surface of the flow inlet opening (15).

Abstract: The present invention relates to a method for balancing a wind turbine. The method includes the steps of a) measuring at least one property that is dependent on a motor workload of at least one yaw motor 52 of a soft yaw system 5 during a period of time, b) calculating an unbalance based on the measurement of step a), c) determining a pitch offset angle for at least one turbine blade 41 based on the calculation of step b), and d) changing the pitch of the at least one turbine blade according to the pitch offset angle of step c) for decreasing the unbalance. The present invention also relates to a system for balancing a wind turbine.

Abstract: A method and apparatus for control of redundant devices in a wind turbine is provided, comprising operating a first redundant device and at least one other redundant device such that the first redundant device is expected to fail before any of the at least one other redundant devices.

Abstract: A system and method for pitching a rotor blade in a wind turbine are disclosed. The method includes collecting in an individual pitch controller for the rotor blade a pitch offset angle relative to a collective pitch angle. The method further includes determining a synchronized pitch offset angle. The method further includes, after an emergency condition occurs, pitching the rotor blade towards the synchronized pitch offset angle.

Abstract: An axial fan, having an inner electric motor and a fan wheel connected to the electric motor so as to rotate with it and has a plurality of wheel blades defining a blade length and extend outwardly from the electric motor. A fan housing surrounds the fan wheel. The fan housing is connected to the motor via holding struts which extend to the outside from the motor to the fan housing. A motor housing is provided on the motor behind the fan wheel and accommodates a motor electronics system. A flow duct having an inflow opening and an outflow opening is fastened to the motor behind the fan wheel such that the inflow opening is arranged offset to the outside with respect to the outflow opening. The outflow opening is oriented in such a way that an air flow which exits the outlet opening is guided onto the motor housing.

Abstract: A method for preventing a possible overspeed of a wind turbine rotor with at least one rotor blade is provided. The method includes detecting a yaw misalignment of the rotor, and imposing a restriction on changes of a pitch angle towards a feathered position of the at least one rotor blade after detecting the yaw misalignment. Further, a wind turbine having a rotor and a control system configured to prevent a possible overspeed of the rotor is provided.

Abstract: In a method for operating a vehicle which has a first axle, a second axle, a unit for determining slipping of at least one wheel of the second axle on a ground surface, and a braking device associated with the wheel, a drive torque is applied to the first axle and the second axle via a central differential, and, in the event of slipping of the wheel, a braking torque required to prevent the slipping being determined. A setpoint braking torque is set on the braking device, which is less than the required braking torque, and the part of the drive torque supplied to the first axle is increased.

Abstract: The present invention relates to a method for balancing a wind turbine. The method includes the steps of a) measuring at least one property that is dependent on a motor workload of at least one yaw motor 52 of a soft yaw system 5 during a period of time, b) calculating an unbalance based on the measurement of step a), c) determining a pitch offset angle for at least one turbine blade 41 based on the calculation of step b), and d) changing the pitch of the at least one turbine blade according to the pitch offset angle of step c) for decreasing the unbalance. The present invention also relates to a system for balancing a wind turbine.

Abstract: A method for preventing a possible overspeed of a wind turbine rotor with at least one rotor blade is provided. The method includes detecting a yaw misalignment of the rotor, and imposing a restriction on changes of a pitch angle towards a feathered position of the at least one rotor blade after detecting the yaw misalignment. Further, a wind turbine having a rotor and a control system configured to prevent a possible overspeed of the rotor is provided.

Abstract: A method of adjusting a yaw angle of a wind turbine. The wind turbine includes a nacelle that is rotatably coupled to a tower. The method includes coupling a yaw drive assembly to the nacelle for adjusting an orientation of the nacelle with respect to a direction of wind. A first sensor that is coupled to the wind turbine transmits at least a first monitoring signal that is indicative of an operating condition of the wind turbine to a control system. A yaw angle of the nacelle with respect to the direction of wind is calculated by the control system based at least in part on the first monitoring signal. The yaw drives assembly is operated to adjust a yaw of the nacelle based at least in part on the calculated yaw angle.

Abstract: A system and method for pitching a rotor blade in a wind turbine are disclosed. The method includes collecting in an individual pitch controller for the rotor blade a pitch offset angle relative to a collective pitch angle. The method further includes determining a synchronized pitch offset angle. The method further includes, after an emergency condition occurs, pitching the rotor blade towards the synchronized pitch offset angle.

Abstract: A wind turbine (10) is provided. The wind turbine includes a rotor (18), at least one rotor blade (22) coupled to the rotor, and a yaw system (92). The yaw system (92) includes at least one yaw motor (94) for adjusting a yaw angle of the wind turbine (10). The yaw system (92) is configured for generating a yaw drive signal corresponding to at least one of: i) a property from the at least one yaw motor (94); or ii) a control signal for operating the at least one yaw motor. The wind turbine (10) further includes an asymmetric load control assembly (100) configured to receive the yaw drive signal. The asymmetric load control assembly (100) is further configured to mitigate an asymmetric load acting on the rotor (18) using the yaw drive signal. A control system for operating a wind turbine (10) and a method thereof are also provided.

Abstract: The present invention relates to a yaw system 5 for a windmill 1, the windmill comprising a tower 2 and a nacelle 3, the tower and the nacelle being joined by the yaw system and the yaw system further comprising a bearing fixed to the tower, on which bearing the nacelle rests and slides in a yawing movement, and at least one yaw motor arranged to allow the nacelle to perform a rotary motion along the bearing, wherein the yaw system 5 further comprises control means 8 for continuously operating the at least one yaw motor in such a way that the yaw motor strives to manoeuvre the nacelle according to a setpoint.

Abstract: A radial fan wheel arrangement includes a circular bottom plate (2) and a circular cover plate (3) with a central inflow opening (4), as well as wheel blades (6) running between the bottom plate (2) and the cover plate (3). Pocket-shaped recesses (9) are configured at least on one side of a plate surface in the space between the wheel blades (6) in an outer edge area of the cover plate (3) or the bottom plate (2) or both. At least one counterweight (13) is mounted on at least one of the two plates (2, 3) on a plate edge in an area of the pocket-shaped recesses (9).

Abstract: A method of adjusting a yaw angle of a wind turbine. The wind turbine includes a nacelle that is rotatably coupled to a tower. The method includes coupling a yaw drive assembly to the nacelle for adjusting an orientation of the nacelle with respect to a direction of wind. A first sensor that is coupled to the wind turbine transmits at least a first monitoring signal that is indicative of an operating condition of the wind turbine to a control system. A yaw angle of the nacelle with respect to the direction of wind is calculated by the control system based at least in part on the first monitoring signal. The yaw drives assembly is operated to adjust a yaw of the nacelle based at least in part on the calculated yaw angle.

Abstract: The present invention relates to a compact fan, comprising a fan wheel, in particular a radial fan wheel (1), which is fastened on a rotor of an external rotor motor (82). The fan wheel (1) is supported between a front plate (8) having an air inlet opening (9), which is central, and a motor mount (11). The front plate (8) and the motor mount (11) are connected to one another via multiple spacers (12), which are disposed around the circumference. The front plate (8) and the motor mount (11) are formed as plastic or metal spray parts. The spacers (12) are formed as plastic or metal parts entirely or partially in one piece to the front plate (8) and/or the motor mount (11).

Abstract: A centrifugal pump with an impeller which has a single helically-formed blade and which is not sensitive to sand abrasion or seizing of the impeller is achieved by providing the impeller (1) with a shielding plate (3) arranged on the suction side which transitions from an axial course given at the suction inlet of the impeller into a radial course, by providing that the blade entry angle (&bgr;1) in the area which is in danger of cavitation in the event of an abrupt onset of flow is at least 5° smaller than the angle of incident flow (&bgr;0), and thereafter the blade angle &bgr; in the axial region of a meridian section through the impeller (1) increases at least to the magnitude of the blade exit angle (&bgr;2), and finally a blade angle (&bgr;) exceeding the blade exit angle (&bgr;2) in the radial area of the meridian section decreases back down to the magnitude of the blade exit angle (&bgr;2).

Abstract: An impeller of a centrifugal pump for transporting dirty liquids has transport elements, for example back-vanes or grooves disposed on the pressure side of a cover disk. The transport elements are arranged asymmetrically and are limited to one arc sector of the cover disk to create a transverse stream that rotates with the impeller. Solids which have penetrated into the space to the side of the wheel are carried out by this stream in the direction of the transport elements.