Wind Turbine Pitch Assembly Overspeed Control
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Solution Overview
Problem
Large wind turbines face increased loads from wind shears, yaw misalignment, and turbulence, leading to significant fatigue on rotor blades and other components, and existing pitch systems are unable to operate during power loss or control system malfunctions, resulting in potential overspeed and damage.
Innovation Solution
A pitch assembly system that includes a pitch drive system and overspeed control system, allowing the rotor blade to be rotated about a pitch axis to reduce speed during overspeed conditions, and enabling operation during power loss or control system malfunctions, using a power generator to provide continuous power to the pitch assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pitch system is designed to operate during power loss or control system malfunction, then reliability is improved, but device complexity increases due to additional power generator and control systems
Solution Approach 1:
The power generator is pre-installed and pre-configured within the pitch assembly, ready to immediately take over power supply functions when the main control system fails. This preliminary preparation ensures that the backup power capability is already in place without requiring complex real-time decision-making or system reconfiguration during emergencies.
Solution Approach 2:
The power generator acts as an intermediary power source between the main electrical system and the pitch drive motors. When the main control system fails, the power generator mediates by providing alternative power supply to keep the pitch system operational, effectively decoupling the pitch control reliability from the main electrical system status.
2Productivity
If larger rotor components are used to increase electrical power output, then productivity is improved, but fatigue damage increases due to increased loads from wind shears and turbulence
Solution Approach 1:
The overspeed control system continuously monitors rotor speed and provides feedback control by automatically adjusting blade pitch when overspeed conditions are detected. This closed-loop feedback mechanism allows larger rotors to operate safely by dynamically adjusting aerodynamic loads, preventing excessive fatigue damage while maintaining high power output capability.
Solution Approach 2:
The pitch system enables dynamic adjustment of blade pitch angles in response to varying wind conditions and rotor speed. This dynamic control allows the larger rotor components to adapt to changing loads from wind shears and turbulence, optimizing power extraction while reducing fatigue accumulation through real-time aerodynamic adjustment.
Data Source
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AI summary
A pitch assembly (66) for use with a wind turbine (10) including a rotor (18) and at least one rotor blade (22) coupled to the rotor (18) is provided. The pitch assembly includes a pitch drive system (68) coupled to the rotor blade for rotating the rotor blade about a pitch axis (34), and at least one sensor (70) mountable with respect to the rotor for sensing an overspeed of the rotor, the sensor is communicatively coupled to the pitch drive system, and the pitch drive system configured to rotate the rotor blade when the sensor senses rotor overspeed.