Abstract: In order to reduce the weight of a hybrid propulsion system for a multi-rotor rotary-wing aircraft, the system comprises at least one inverter configured to supply power in parallel to multiple electric motors intended to drive the corresponding propellers of the system.

Abstract: A computer-implemented method comprising: controlling input of data quantifying damage received by a compressor of a gas turbine engine into a first machine learning algorithm; receiving data quantifying a first operating parameter of the compressor as an output of the first machine learning algorithm; and determining operability of the compressor by comparing the received data quantifying the first operating parameter of the compressor with a threshold.

Abstract: Provided is a safety stop valve arrangement of a hydraulic blade pitch system of a wind turbine, including an accumulator arrangement connected over a hydraulic line to a piston of the hydraulic blade pitch system; a redundant set of safety valves arranged between the accumulator arrangement and the piston; a small-orifice restriction nozzle arranged to determine a first rate of hydraulic fluid flow in response to a safety stop input; at least one speed-select valves arranged; and at least one large-orifice restriction nozzle arranged to determine a second rale of hydraulic fluid flow in response to a positive rotor acceleration input, wherein the second rate of fluid flow is faster than the first rate of fluid flow. A safety stop assembly of a wind turbine with hydraulic blade pitch systems and a method of performing a safety stop sequence is also provided.

Abstract: Systems and methods for predicting a surge event in a compressor of a turbomachine are provided. According to one embodiment of the disclosure, a system may include one or more computer processors associated with the turbomachine. The one or more computer processors may be operable to receive a plurality of performance parameters of the compressor and analyze the plurality of performance parameters to determine corrected performance values of the performance parameters. Based at least partially on the corrected performance values, a compressor efficiency may be determined. The processor may be further operable to standardize the compressor efficiency for a standard mode of operation, ascertain historical performance data associated with the standard mode of operation, and analyze the compressor efficiency based at least partially on the historical performance data. Based on the analysis of the compressor efficiency, a surge event may be selectively predicted.

Abstract: The present subject matter is directed to a system and method for improving speed control of a pitch drive system of a wind turbine. In one embodiment, the pitch drive system includes a direct current (DC) motor having an armature and a series-field winding, a battery assembly having a positive terminal and a negative terminal, and a current-controlling device configured in series between the positive terminal of the battery assembly and the series-field winding. The battery assembly is configured to supply power to the pitch drive system and the current-controlling device is configured to supply current to the series-field winding so as to ensure a field flux does not equal zero. Thus, the current-controlling device has the effect of limiting the maximum speed of the DC motor.

Abstract: A hybrid drive system for aircraft, in particular helicopters, with at least one energy generating module having an internal combustion engine and a generator that can be powered by the latter to generate electrical energy, and at least one electric motor for powering a drive means of the aircraft.

Abstract: A vibration attenuator for an aircraft has at least one weight mounted in a rotating system of a rotor hub of the aircraft, each weight being rotatable about an axis of rotation of the hub relative to the hub and to each other weight. Drive means are provided for rotating each weight about the axis of rotation at a selected speed for creating oscillatory shear forces that oppose and attenuate rotor-induced vibrations having a selected frequency. A vertically oriented vibration attenuator is configured to oppose and attenuate vertical rotor induced oscillatory forces that would otherwise travel vertical down the rotor mast and into the airframe.

Abstract: A control system for a turbine blade, including: an operational control element for generating and outputting an operational control signal, the operational control signal for non-emergency operation of a motor for controlling pitch of the turbine blade; an emergency control element, separate from and different from the operational control element, for generating and outputting an emergency control signal for emergency operation of the motor; and, an output stage element for receiving the operational and emergency control signals and for selecting one of the operational or emergency control signals, and with a means for receiving power for operation of the motor and with a means for providing the received power to the motor according to the selected operational or emergency control signal.

Abstract: A device for locking a rotor blade of a wind turbine which has an adjustment system for the blade pitch angle of the rotor blade, wherein the adjustment system has a drive which features a motor and a gearbox with an input shaft that bears an external toothing, characterized by a locking pin rotatably mounted around its longitudinal axis, which engages with the external toothing in a locking position, and releases the external toothing in an unlocked position, wherein the locking pin has an end portion whose free end stands eccentric to the longitudinal axis of the locking pin.

Abstract: A system for controlling propeller blade pitch in a turboshaft engine, including: a first track connected to a propeller blade, of which the rotation provides for the setting of the incidence of this blade; a second track; a member actuating the first track, arranged between the first and second tracks, and having a recessed angular portion; and at least one locking member provided between the first and second tracks, housed in the recessed angular portion and in the notch. The locking member can occupy a normal over-center position rendering the first and second tracks integral in rotation, and a release position authorizing the displacement in rotation of a unit including the first track, the locking member, and the actuating member.

Abstract: A system for controlling pitch of a propeller blade of a turboshank engine, including two automatic locking members making it possible, depending on their controlled position, to lock rotation of a blade root in both directions of rotation, or to allow the rotation of the blade root support in either of the two directions.

Abstract: A system for driving a wind turbine blade (46) into a feathered position during an emergency stopping process of a wind turbine rotor. The system comprises a hydraulic actuator (3) functionally connected to the blade (46) for changing the pitch of the blade (46) during movement of the hydraulic actuator (3) and an emergency accumulator (8) connected to the hydraulic actuator (3) for driving the hydraulic actuator (3) with fluid from the emergency accumulator (8). The emergency accumulator (8) comprises a resilient member for accumulating the fluid in the emergency accumulator (8) under resilient pressure or a weight member (74) comprising a weight member upon the fluid in the emergency accumulator. The resilient member (14) or weight member (74) is configured for driving the fluid out of the emergency accumulator due to the expansion or retraction of the resilient member.

Abstract: A turboprop having a set of variable-pitch rotary blades constrained to rotate with a rotary support. In order to vary its pitch, each blade of said set is coupled to a specific hydraulic actuator carried by the rotary support.

Abstract: Controller for a blade adjustment angle for at least one rotor blade of a wind power plant, in which a first controller branch is switched for the determination of the blade adjustment angle depending on the operating states of the wind power plant, wherein at least one differentiating member is provided in the switched first controller branch.

Abstract: The present invention relates to a wind turbine assembly comprising a turbine having turbine blades, said turbine being arranged to generate a rotational energy as the turbine blades are engaged by a wind, characterized in that said wind turbine assembly further comprises an emergency brake that is operationally connected to the turbine blades for pitching the turbine blades towards a rest position by the rotational energy of the turbine, when the emergency brake is activated.

Abstract: A method for monitoring wear of a blade pitch brake within a rotor blade pitch control system of a wind turbine is described. The rotor blade pitch control system includes a blade pitch actuator. The method includes engaging the blade pitch brake and measuring a blade pitch displacement while the blade pitch brake is engaged. The method further includes determining a brake wear level based on the measured blade pitch displacement while the blade pitch brake is engaged, and generating a brake wear level output signal corresponding to the brake wear level.

Abstract: A mechanical emergency brake for a wind turbine is provided, said mechanical emergency brake comprising a spiral spring with a loop at its outer end, a cassette for accommodating said spring and a casing for receiving said cassette and said spring, wherein said casing comprises a retention pin to which the loop of the spring can be fixed.

Abstract: A method for monitoring wear of a blade pitch brake within a rotor blade pitch control system of a wind turbine is described. The rotor blade pitch control system includes a blade pitch actuator. The method includes engaging the blade pitch brake and measuring a blade pitch displacement while the blade pitch brake is engaged. The method further includes determining a brake wear level based on the measured blade pitch displacement while the blade pitch brake is engaged, and generating a brake wear level output signal corresponding to the brake wear level.

Abstract: A method facilitates lubrication of components. The method includes coupling a blade to a pitch control mechanism such that a bearing is positioned between the blade and the pitch control mechanism. The method further includes coupling a control system to the pitch control mechanism and configuring the control system to control the blade pitch mechanism for controlling movement of the blade and rotate the blade from a first position to a second position when a predetermined amount of time has elapsed.

Abstract: A wind turbine system is provided with a wind turbine rotor, a pitch control mechanism, and an emergency power supply mechanism. The wind turbine rotor includes a blade having a variable pitch angle. The pitch control mechanism drives the blade to control the pitch angle. The emergency power supply mechanism generates electric power from rotation of the wind turbine rotor and feeds the electric power to the pitch control mechanism, in response to occurrence of an accidental drop of a system voltage of a power grid.

Abstract: A wind energy plant with a nacelle, the azimuth orientation of which is motor-driven adjustable via an adjustment device, the adjustment device having at least one asynchronous motor with gearbox and at least one holding brake, wherein a control unit for the asynchronous motor is provided, which limits the moment occurring on the asynchronous motor to a predetermined maximum value.

Abstract: A method and system for detecting precursors to compressor stall and surge in which at least one compressor parameter is monitored to obtain raw data representative of said at least one compressor parameter. The raw data is pre-processed using a frequency demodulator to produce pre-processed data, and the pre-processed raw data is post-processed using a Kalman filter to obtain stall precursors.

Abstract: An apparatus for monitoring the health of a compressor having at least one sensor operatively coupled to the compressor for monitoring at least one compressor parameter, a processor system embodying a stall precursor detection algorithm, the processor system operatively coupled to the at least one sensor, the processor system computing stall precursors. A comparator is provided to compare the stall precursors with predetermined baseline data, and a controller operatively coupled to the comparator initiates corrective actions to prevent a compressor surge and stall if the stall precursors deviate from the baseline data, the baseline data representing predetermined level of compressor operability.

Abstract: A control system for preventing a compressor stall in a gas turbine engine includes means for sensing an aerodynamic signal indicative of an impending stall condition. The weak stages of the compressor amplify an upstream disturbance originating in the low pressure compressor or fan, resulting in a discrete frequency disturbance, which is an effective stall precursor. The control system also includes means, responsive to the sensed signal, for processing the signal by isolating the relevant frequencies of the sensed signal, calculating the magnitude of the relevant portions of the sensed signal, comparing the sensed signal to a predetermined threshold indicative of a healthy compressor, and for providing a processed signal indicative of an impending stall condition. The control system further includes means, responsive to the processed signal, for providing an output to initiate corrective action to prevent the impending stall condition.

Abstract: A system for changing pitch in aircraft propfans is disclosed, in which a motor, located at a stationary position, changes pitch of the blades by of a gear train. Three features of the system are that a feather brake can override the motor and drive the blades toward feather; a unison brake can prevent pitch from undergoing excursions toward fine pitch when propeller speed exceeds a limit; and the motor is non-rotating in the absence of pitch change. A pair of such systems can be used in a counterrotating propfan system, in order to independently change pitch of the propfans.

Abstract: The invention concerns a pitch change mechanism for an aircraft propeller in which a common ring gear (51) changes pitch of all propeller blades on a given rotor simultaneously. Motion of the ring gear (51) is induced by a planet (40)-and-carrier (101) system driven by a pinion (110). Acceleration of the pinion causes a change toward flat pitch. Deceleration of the pinion causes change toward feathered pitch. If the motor driving the pinion fails, a large deceleration occurs, driving the blades to a safe, feathered position.

Abstract: Apparatus and methods for adjusting the pitch of a fluid reactive blade member carried upon a rotor in response to a speed difference between the rotor and a reference speed shaft.

Abstract: A windpower system includes a support and a turbine having a shaft rotatively mounted to the support. The turbine has variable pitch blades whose pitch is controlled by the differential motion of a rotary control shaft coaxial with the turbine shaft and the turbine shaft itself so that the blade pitch can be varied by a stationary motor without requiring any slip rings or other such wear-prone couplings. In the event of a power failure, rotary motion of the control shaft is prevented so that the turbine blades are feathered solely due to the force developed by the rotating turbine. Also, if the turbine is used to generate electrical power, an induction generator coupled to the turbine shaft is employed whose shaft speed is indicative of generator output power.