Active Load Control Strategies for Wind Turbines

Vertical axis wind turbine generator with improved torque and noise performance compared to traditional vertical axis wind turbines. The generator has a vertical rotor shaft and multiple blades attached. The blades are divided into fixed and movable sections. The movable sections can close or open a central wind hole in the fixed sections. This allows optimizing blade pressure and torque. When backwind blows, the movable sections close the wind hole to maximize pressure. When headwind blows, they open the wind hole to minimize pressure. This reduces counter-torque from wind forces and noise compared to traditional vertical axis wind turbines.

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Vertical axis multi-stage wind turbine generator with reduced counter-torque wind pressure and improved stability for high wind speeds. The turbine has multiple stages of rotor blades mounted vertically between conical guide plates. Each rotor blade has a ball-netted wind hole that can open or close depending on wind direction. When the blade is accelerating into the wind, the hole opens to increase blade speed. When the blade is decelerating, the hole closes. This allows higher blade speeds and reduces counter-torque force compared to fixed wind holes. The turbine also has reinforcing poles between the guide plates to withstand high winds.

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Protecting wind turbine generators from mechanical damage during heavy loads by preventing rotor-stator contact. The method involves adding a sliding pad connected to the stator. If the rotor tilts past a critical angle due to gravity forces, it contacts the sliding pad instead of the stator, preventing damage. The sliding pad provides a controlled contact point to avoid direct rotor-stator contact when the rotor tilts excessively under heavy loads.

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Vertical wind turbine design with improved blade control and reduced energy loss for higher efficiency. The vertical turbine has blades that pitch continuously throughout rotation, controlled by cam disks, to optimize performance in partial load winds. The blades are supported by bearings at multiple points to enable independent pitching between sections. The pitch motors are enclosed in a housing with support ribs to transmit forces. A casing around the pitch motor reduces aerodynamic drag. The turbine has sensors on the blades for wind speed/direction feedback. A control device adjusts blade angles based on sensor data.

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A direct-drive wind turbine design that reduces the air gap between the stator and rotor without increasing weight or cost. The turbine has a radial elastic fixing mechanism that maintains precise air gap control. The hub and frame have concentric guiding rails/wheels/bearings that rotate together. Elastic fixing elements compress the rails/wheels radially against each other. This allows radial movement while preventing axial and tangential misalignment. This provides stable air gap control without needing heavy bearings or complex systems. The elastic fixings can be separate carriages or sliding surfaces. The turbine also has options like rails/wheels or slide bearings, and internal space housing.

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A wind turbine drivetrain assembly that prevents axial displacement of the bearing without using rings that are difficult to install. The assembly has the bearing, rotor shaft, and a component like a gearbox with opposed annular faces. Bolts are inserted through tapped holes in the faces to connect them. The bolt heads contact the opposing face. This creates a bridge of bolts that prevents axial movement. The bolts can be tightened after assembly to compress the faces together. This allows easier assembly compared to tight fitting rings or threaded shafts.

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Self-regulating wind turbine generator that can adjust output voltage without mechanical components like blade pitch control or yaw systems. The generator has a rotor spinning with the wind turbine and a stator that can move inside the rotor's magnetic field. An actuator moves the stator closer to the rotor to increase voltage below a threshold and farther away to limit voltage above the threshold. This self-regulation allows maximum voltage extraction without overloading the system in high winds.

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Control method for wind turbines configured as virtual synchronous machines (VSMs) to improve grid stability and reduce mechanical loads after faults. The method involves controlling the wind turbine's power output based on the synchronous machine angle, using high-pass filtered rotational speed to determine damping power. It also uses comparisons of DC link voltage and grid power to determine chopper power. This allows the wind turbine to provide grid-forming properties similar to a synchronous generator while avoiding power oscillations and excessive mechanical loads after faults.

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Controlling a wind turbine's generator operation to reduce tonality noise when the air gap thickness between the rotor and stator changes. The control regulation is adapted based on the air gap thickness. This involves selecting or setting the generator output, torque, or voltage in a manner dependent on the air gap. It also involves modifying the rotational speed avoidance range and shifting it as the gap changes. This targets operating points to avoid tonality issues as the gap varies. It can be based on gap sensors or estimated gap changes.

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System for measuring blade root loads in wind turbines without physical contact. It uses contactless sensors fixed to the hub to detect displacements of reference planes on the blades as they move. This allows estimating blade root loads without intrusive sensors. The hub-mounted sensors detect blade-relative displacements of the fixed reference planes. A controller processes the sensor data to determine blade root bending moments. This enables real-time load monitoring and control to optimize blade loads and pitch angles.

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Preventing failure of pitch bearings in wind turbine rotor blades due to lack of lubrication. A sensor in the pitch bearing measures vibration, noise, and temperature changes. When the sensor signal indicates weak lubrication, the blade pitch is adjusted to prevent bearing failure. This prevents stand still marks, false brinelling, and fretting corrosion on the bearing raceway. The pitch is changed to move the load and allow lubricant to reach the contact surface. The sensor signal is compared to initial levels/patterns to determine when pitching is needed.

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Reducing sound emissions in wind turbine generators using active rectifiers with closed-loop control. The rectifiers are controlled based on the rotor position and number of pole pairs to reduce torque ripple and noise. The rectifier currents are predefined as equivalent variables. This involves modulating the partial currents of the two stators with the sixth harmonic instead of the twelfth harmonic to reduce magnetic forces and noise.

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Wind apparatus that maximizes the amount of kinetic energy captured from an air flow by changing the aerodynamic behavior of its blades over time in response to the air flow. The apparatus has blades that move along curved guides when hit by wind, rotating to optimize capture. This allows the blades to respond to changing wind directions and speeds, increasing energy capture compared to fixed blade designs. The blade motion is transmitted through mechanisms to turn shafts and generate electricity.

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A wind energy harvesting system that captures more energy from wind than conventional wind turbines. It uses a unique configuration of wind collectors, boosters, and rotatable exit conduits to extract more mechanical torque from wind. The system collects wind in inner and outer wind collectors, boosts the flow rate through a booster arm, then expels it through a rotatable exit conduit. The thrust force from exiting wind turns the exit conduit, which can be converted to electrical power. This provides a more efficient transformation of wind kinetic energy into usable mechanical torque compared to conventional lift-based wind turbines.

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Condition monitoring system for wind turbines that presents an optimal amount of power suppression based on damage levels to bearings and gears. The system uses acceleration sensors to measure vibrations, calculates diagnostic parameters from the data, determines damage levels, and shows the appropriate power suppression level on the monitoring terminal. This allows continued operation with reduced power when bearings or gears are damaged, preventing sporadic failures and extending life, rather than sudden failures when continuing normal power. The optimal suppression levels are determined based on vibration analysis instead of human judgment.

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Determining a pitch reference for a wind turbine blade control system without physically attaching the blade. The method involves attaching the hub and pitch bearing rings, then emitting light from a sensor inside the hub parallel to the blade pitch axis. The blade ring is rotated to align the light path with a target attached to it. This change in light detection indicates the pitch reference.

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Turbine design for wind power generation that improves efficiency by allowing blades to expand and close as the turbine rotates. The blades pivot on a rotary shaft and have stoppers to limit expansion angles. Elastic members connect the blades to the shaft. In the expanded position, the blades face the stoppers to capture more wind force. In the closed position, the blades are near the shaft to reduce drag. This eliminates negative power during blade reversal. The turbine can be integrated in a channel structure where the blades touch the walls when closed. The blades expand when diverted fluid flows between the walls. This allows high fluid speed entry and extraction. The turbine also integrates anti-friction members and cover sheets for pivotal motion.

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Vertical axis wind turbine with improved vane control for reduced noise and drag. The turbine has vertical blades with rotating vanes that open to reduce drag when facing wind and close to generate torque when facing away from wind. The vane pivots 180 degrees. To slow vane movement and prevent impact at extremes, biasing hinges and stops limit vane rotation near 0 and 180 degrees. This reduces vane speed and contact noise compared to sudden stops.

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Wind turbine design to mitigate resonant vibrations and noise. The wind turbine has a vibration source, like a generator or gearbox, and a component, like a tower or blade, that can resonate at a frequency. To prevent resonant amplification, a resonator module is added to the component at a quarter-length point along its resonant wavelength. This allows the resonator to vibrate at the component's resonant frequency, cancelling out some of the component's vibrations.

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A transmission gearing for wind turbines and electric vehicles that is lighter than conventional planetary gears, more robust to shock and impact loads, and has fewer components. The gearing replaces some of the heavy planetary pinions with drive belts. The belts connect the planetary shafts to high-speed shafts instead of using more pinions. This reduces weight and simplifies the gearing. The belts also absorb and dampen shock forces.

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