955 results about "Rotor speed" patented technology

A variable speed wind turbine employing a rotor connected to a multiplicity of synchronous generators with wound field or permanent magnet rotors. A passive rectifier and an inverter are used for power transfer back to the grid. A Turbine Control Unit (TCU) commands a required generator torque based on rotor speed and power output of the turbine inverters. Torque is controlled by regulating the DC current by control of the inverter. A main-shaft-damping filter is provided by measurement of the DC bus voltage. In high winds the turbine remains at a constant average output power through a constant torque command and a varying pitch command to a rotor pitch servo system. A set point is fixed at the inverter output such that output VAR load is minimized running the turbine at very nearly unity power factor. Dynamic VAR and power factor control is provided by a separate VAR apparatus.

A variable speed wind turbine employing a rotor connected to a multiplicity of synchronous generators with wound field or permanent magnet rotors. A passive rectifier and an inverter are used for power transfer back to the grid. A Turbine Control Unit (TCU) commands a required generator torque based on rotor speed and power output of the turbine inverters. Torque is controlled by regulating the DC current by control of the inverter. A main-shaft-damping filter is provided by measurement of the DC bus voltage. In high winds the turbine remains at a constant average output power through a constant torque command and a varying pitch command to a rotor pitch servo system. A set point is fixed at the inverter output such that output VAR load is minimized running the turbine at very nearly unity power factor. Dynamic VAR and power factor control is provided by a separate VAR apparatus.

Electric rotary current machine that includes a casing and a stator fitted within the casing. The stator has at least one stator winding. At least two mechanically separate rotors are rotatably mountable within the casing and have a same axis of rotation. In this way, each rotor has electromagnetic interaction with the stator when the stator is electromagnetically active. The rotor speeds are the same or different. A motor control is arranged to control a supply to at least one of said at least one stator winding by superposition of at least two rotary field components, one for each rotor.

A variable speed system for use in systems, such as, for example, wind turbines, is described. The system comprises a wound rotor induction generator, a torque controller and a proportional, integral derivative (PID) pitch controller. The torque controller controls generator torque using field oriented control, and the PID controller performs pitch regulation based on generator rotor speed.

The invention discloses a method for improving the estimation accuracy of the rotor position of a permanent magnet synchronous motor. The method comprises the following steps: on the basis of realizing estimation of the rotor position of the permanent magnet synchronous motor by utilizing a pulse-shake high frequency voltage injection method, processing the extracted position estimation error function, eliminating a second harmonic component introduced due to asymmetric motor parameters, so as to obtain a processed position estimation error function, then establishing a phase-locked loop, and adjusting the phase-locked loop to be 0, thus obtaining estimated rotor speed and estimated rotor position. The method disclosed by the invention can effectively inhibit position estimation second harmonic error caused by the asymmetric motor parameters, and the performance of a control system without a position sensor can be improved.

A method and apparatus provide a state observer control system 600 for a motor 106 that uses an extended Kalman filter 330 to predict initial rotor position and afterwards accurately predict rotor position and / or speed under variable types of loading conditions. A control system model 300 is generated that allows variable setting of an initial rotor position to generate estimated rotor position and speed as outputs. The control system model 300 includes an EKF (extended Kalman filter) estimator 330, speed controller 322, a current controller 324, and a variable load component 310. During operation, EKF estimator 330 estimates rotor speed 327 and position 333 based on reference voltages 402, 404 and currents 1325 generated by speed and current controllers 322, 324 and input from frame transformers 326, 328. Additionally, the reference currents and voltages 402, 404, 1325 are frame-transformed to be used as feedback signals 418, 346 in the system 600 and as drive signals to control power to be applied to a motor load 602.

A variable speed system for use in systems, such as, for example, wind turbines, is described. The system comprises a wound rotor induction generator, a torque controller and a proportional integral derivative (PID) pitch controller. The torque controller controls generator torque using field oriented control, and the PID controller performs pitch regulation based on generator rotor speed.

An emergency pitch drive power supply is provided, the emergency pitch drive power supply comprising an auxiliary generator for producing electric power, wherein the auxiliary generator is a permanently excited multi-pole generator adapted to generate sufficient power for a pitch drive of a wind turbine when driven with wind rotor speed, and wherein the auxiliary generator is connected to at least one pitch drive motor of the wind turbine.

A control system for a motor including a rotor comprises a sensorless sensor module that includes a saliency-based estimator module that generates a first rotor position signal based on saliency and a back electromotive force (emf) estimator module that generates a second rotor position signal based on back emf. A selector selects the first rotor position signal for rotor speeds below a first rotor speed and the second rotor position signal for rotor speeds above the first rotor speed. A rotor position sensor senses a position of the rotor and generates a third rotor position signal. A fault detection module senses faults in the rotor position sensor and outputs the third rotor position signal when a fault is not detected and one of the first and second rotor position signals when the fault is detected. An indirect field oriented control (IFOC) system controls the motor based on a selected one of the first, second and third rotor position signals.

A method of stabilizing a jet-powered tri-mode aircraft as the aircraft travels in a helicopter mode, a compound mode, and a fixed-wing mode is disclosed. The method includes receiving a plurality of velocity vector component values and velocity vector commands derived from either (1) a number of pilot operated controllers or (2) a commanded array of waypoints, which are used for fully automated flights, and a rotor speed reference value, which is decreased with increasing forward speed to unload the rotor, thereby permitting conditions for stopping the rotor in flight. Stabilization of the commanded velocity vector is achieved in all modes of flight using blended combinations of rotor swashplate controls and aerodynamic controls such as elevons, canards, rudders, and a horizontal tail. Stabilization to the commanded velocity vector includes a plurality of control constraints applied to the pilot stick controllers that prevent penetration of envelope limits.

The invention is directed toward a UAV having a plurality of rotors position on axles extending longitudinally from a fuselage. The axles articulate the rotors from a vertical position, where the rotors provide lift, to a horizontal position, where the rotors provide thrust. The UAV is configured such that the voltage provided to each rotor may be varied to adjust rotor speed, and thus thrust, independently, giving the UAV enhanced maneuverability.

Reduction in power output or rotor speed of a wind turbine above a defined limit value, the reduction not being implemented based on the measured wind speed, but on an input value which on one hand is easily detected physically and by control technology and on the other hand is a good indicator of mechanical stresses on the wind turbine. The invention uses the rotor-blade angle as the input value in a manner that starting at the limit value, the reduction in power output or in rotor speed is adjusted as a function of the rotor-blade angle.

A high efficiency magnetic core electrical machine includes magnet and coil assemblies that may be axially stacked to form modules. The magnet sub-assemblies include magnet locators on which multiple permanent magnets are arranged, and the coil sub-assembly includes a pair of bobbin holders supporting multiple bobbins and magnetic cores that extend through the bobbins and through openings in the bobbin holders to form magnetic poles that face the permanent magnets. The permanent magnets and magnetic poles may be arranged in various zero-cogging configurations, including one in which the permanent magnets on opposite sides of the coil assembly are skewed relative to each other to cause cogging force cancellation. In addition, a power matching circuit may be used to optimize the output power of the electrical machine to rotor speed when the electrical machine is used as a generator.

A transmission gearbox for a rotary-wing aircraft includes a main gearbox and a variable speed gearbox in meshing engagement with the main rotor gearbox. The variable speed gearbox permits at least two different RPMs for the main rotor system without disengaging the engine(s) or changing engine RPMs. The variable speed gearbox includes a clutch, preferably a multi-plate clutch, and a freewheel unit for each engine. A gear path drives the main gearbox in a “high rotor speed mode” when the clutch is engaged to drive the main rotor system at high rotor rpm for hover flight profile. A reduced gear path drives the main gearbox in a “low rotor speed mode” when the clutch is disengaged and power is transferred through the freewheel unit, to drive the main rotor system at lower rotor rpm for high speed flight. The variable speed gearbox may be configured for a tail drive system that operates at a continuous speed, a tail drive system that changes speed with the main rotor shaft or for no tail drive system.

A method and system is provided for identifying in-range sensor faults in a gas turbine engine, by observing the tracked component qualities in an embedded model and recognizing anomalous patterns of quality changes corresponding to sensor errors. An embedded model of the engine is employed to estimate sensed parameters such as rotor speeds, temperatures and pressures, as well as other parameters that are computed based on input parameters. Each major rotating component of the engine, including the fan, compressor, combustor, turbines, ducts and nozzle is individually modeled. Sensor failures are detected by identifying anomalous patterns in component quality parameters. A library of anomalous patterns is provided for comparing quality parameters generated by a tracking filter with the library of anomalous patterns. If a pattern is matched, a sensor may be eliminated from the tracking filter and the estimated model parameter used to avoid corrupting the model quality parameters.

An electrical machine, such as a switched reluctance motor, has a rotor and at least one electrically energizable phase winding. A control map is derived during production that includes a predetermined advance angle profile representing the energization of the phase winding with respect to the angular position of the rotor over a range of rotor speeds. This is stored in memory in a controller together with an angle correction factor to be applied to a predetermined portion of the advance angle profile. The angle correction factor compensates for the difference between a desired input power and the measured input power. The correction factor may be transmitted to the controller by means of radio frequency signals.

An adaptive, sensorless position sensing apparatus (250) derives rotor position of a synchronous machine (200). The apparatus (250) comprises a first rotor position deriving unit (300) for generating first rotor position values by applying a first sensorless rotor position calculation technique, which emulates a resolver; a second rotor position deriving unit (400) for generating second rotor position values by applying a second sensorless rotor position calculation technique; and a rotor position result output unit (450) for outputting rotor position results over a range of rotor speeds as a function of the first rotor position values, the second rotor position values, and rotor speed.

A method for operating a wind turbine. The method includes providing a wind turbine having at least one blade having adjustable pitch angle that is adjusted according to an operational parameter schedule. A blade efficiency parameter is determined in response to a wind speed and a rotor speed. A minimum pitch angle is determined in response to the blade efficiency parameter and the pitch angle of the at least one blade in response to the blade efficiency parameter is maintained to an angle equal to or greater than the minimum pitch angle independent of the operational parameter schedule. A wind turbine plant and a method for servicing a wind turbine are also disclosed.

A transmission gearbox for a rotary-wing aircraft includes a main gearbox and a variable speed gearbox in meshing engagement with the main rotor gearbox. The variable speed gearbox permits at least two different RPMs for the main rotor system without disengaging the engine(s) or changing engine RPMs. The variable speed gearbox includes a clutch, preferably a multi-plate clutch, and a freewheel unit for each engine. A gear path drives the main gearbox in a “high rotor speed mode” when the clutch is engaged to drive the main rotor system at high rotor rpm for hover flight profile. A reduced gear path drives the main gearbox in a “low rotor speed mode” when the clutch is disengaged and power is transferred through the freewheel unit, to drive the main rotor system at lower rotor rpm for high speed flight. The variable speed gearbox may be configured for a tail drive system that operates at a continuous speed, a tail drive system that changes speed with the main rotor shaft or for no tail drive system.

A centrifuge including: a rotor rotating with a sample contained therein; a rotating shaft rotatably engaged with the rotor; a motor rotating the rotor and the rotating shaft; a belt transmitting rotational force of the motor to the rotating shaft; a rotor speed detecting unit detecting a rotation speed of the rotor; a motor speed detecting unit detecting a rotation speed of the motor; and a control unit controlling the motor, wherein the control unit calculates a signal for controlling the rotation speed of the rotor on the basis of a signal from the rotor speed detecting unit and controls the motor on the basis of a signal from the motor speed detecting unit and the calculated signal.

An electrical machine, such as a switched reluctance motor, has a rotor and at least one electrically energizable phase winding. A control map is derived during production that includes a predetermined advance angle profile representing the energization of the phase winding with respect to the angular position of the rotor over a range of rotor speeds. This is stored in memory in a controller together with an angle correction factor to be applied to a predetermined portion of the advance angle profile. The angle correction factor compensates for the difference between a desired input power and the measured input power. The correction factor may be transmitted to the controller by means of radio frequency signals.

A system and method for reducing rotor loads in a wind turbine that includes a brake and one or more rotor blades coupled to a rotor. Upon detection of a loss of counter torque and a blade-pitch failure in at least one rotor blade, a processor reduces a generator overspeed threshold value by a predetermined amount and determines a brake-release threshold value. The brake is applied to slow the rotor if the generator / rotor speed exceeds the reduced generator / rotor overspeed threshold value. In addition, the brake is applied to slow the rotor until the generator / rotor speed is below the brake-release threshold value. The rate of change of the pitch angle of the rotor blade may be varied as the blade moves toward feather in response to the detected blade-pitch failure.

The invention relates to a method for the operation of a wind power plant (11) with a rotor (10) and a rotating apparatus (20, 22, 24) connected with the rotor (10), wherein a rotor speed (nR) and a rotating apparatus speed (n) are interrelated via a specifiable transmission ratio, wherein the rotating apparatus speed (n) is determined, and wherein a rotational speed measurement value (rpmi) is captured for the determination of the rotating apparatus speed (n). The method according to the invention is characterized in that the rotational speed measurement value (rpmi) is corrected with an intermittently variable correction value (rpmi,c) so that the determined rotating apparatus speed (rpmi,f) results, and wherein the determined rotating apparatus speed (rpmi,f) is fed as the actual value into a regulation apparatus (36) of the wind power plant (11).

A method and apparatus for tactile cueing of aircraft controls (21) is disclosed. The apparatus of the present invention warns pilots of approaching limits on certain aircraft performance parameters. The most common warnings are for rotor speed exceeding a moving limit. The present invention uses tactile cueing through the collective stick (21). Tactile cueing means that the pilot does not need to scan the intruments to ascertain proximity to the aforementioned limits. Instead, the pilot can operate the aircraft within proper limits by touch, while maintaining situational awareness outside of the cockpit (20). The method and apparatus of the present invention provides customary friction resistance up to a limit position that is continuously updated. According to the present invention, continued motion of the collective (21) in a direction beyond that limit position results in a breakout force and an increasing resistive force.

A method and apparatus provide a state observer control system 600 for a motor 106 that uses an extended Kalman filter 330 to predict initial rotor position and afterwards accurately predict rotor position and / or speed under variable types of loading conditions. A control system model 300 is generated that allows variable setting of an initial rotor position to generate estimated rotor position and speed as outputs. The control system model 300 includes an EKF (extended Kalman filter) estimator 330, speed controller 322, a current controller 324, and a variable load component 310. During operation, EKF estimator 330 estimates rotor speed 327 and position 333 based on reference voltages 402, 404 and currents 1325 generated by speed and current controllers 322, 324 and input from frame transformers 326, 328. Additionally, the reference currents and voltages 402, 404, 1325 are frame-transformed to be used as feedback signals 418, 346 in the system 600 and as drive signals to control power to be applied to a motor load 602.

A wind driven generator includes a rotor disposed in a cylindrical duct and supported by a frame for rotation in response to wind flowing through the duct. The rotor includes plural circumferentially spaced paralleled rotor blades supported for rotation about a generally horizontal axis. Each blade is supported for pivotal movement to change blade pitch, angle of attack or camber as the rotor rotates. A pitch or camber control motor or self-governing wind vane mechanism is operable to move a circular cam to vary blade pitch or camber to control rotor speed. The duct is mounted on a mast having a base supported on a foundation for pivotal movement to face the wind for maximizing air flow through the duct. Electric power generators are connected to opposite ends of the rotor at respective power output or drive shafts.

Reduction in power output or rotor speed of a wind turbine above a defined limit value, the reduction not being implemented based on the measured wind speed, but on an input value which on one hand is easily detected physically and by control technology and on the other hand is a good indicator of mechanical stresses on the wind turbine. The invention uses the rotor-blade angle as the input value in a manner that starting at the limit value, the reduction in power output or in rotor speed is adjusted as a function of the rotor-blade angle.

A control system for a wind turbine is provided. A pitch-control unit establishes a pitch-reference signal representing a pitch to be set by the pitch-actuator system. A rotor-speed input receives a signal representing a speed of the rotor. A speed-reference input receives a speed-reference signal for the rotor speed. An inclination-signal input receives a signal representing a tower inclination. A pitch-reference output outputs the pitch reference signal. A modification unit is connected to the speed-reference input to receive the speed-reference signal and connected to the inclination-signal input to receive the inclination signal. The modification unit establishes a modification signal based on the inclination signal, to modify the speed-reference signal via the modification signal, and to output a modified-speed-reference signal. The pitch-control unit connected to the modification unit to receive the modified-speed-reference signal and establish the pitch-reference value at least based on the difference between the modified-speed-reference and the rotor-speed signals.

A wind turbine comprising a wind turbine blade with high lift and / or low solidity is provided. The blade is directed towards pitch regulated wind turbines, which are operated at variable rotor speed and have blades longer than about 30 meters. The blade is for example advantageous in that it may provide reduced extreme and fatigue loads at the same or near the same power production.