Wind Turbine Main Bearing Load Control Using Fibre Optic Strain Sensing
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Solution Overview
Problem
Large-diameter slim-profile bearings in wind turbines face challenges in maintaining consistent contact forces and load profiles due to flexing and wear, leading to uneven load distribution and potential skidding of rollers, which can cause detrimental effects on the bearing and adjacent components.
Innovation Solution
A method and active control assembly that utilize fibre optic sensors to detect strain at multiple positions around the bearing, generating a control signal to dynamically adjust the load profile, which can include adjusting blade pitch or applying additional force to the bearing, and a closed-loop control process to maintain optimal load distribution and temperature management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If large-diameter slim-profile bearings are used to achieve compact design and high stiffness, then the bending- and torsional stiffness are improved, but the design complexity and difficulty of maintaining consistent contact forces increase
Solution Approach 1:
The patent implements dynamic load adjustment mechanisms that actively modify the bearing load profile during operation based on real-time measurements. This dynamic approach compensates for the inherent complexity of slim-profile bearings by adapting the pre-loading forces to maintain optimal contact conditions throughout the bearing circumference, thereby managing the design complexity through active control rather than static design alone
Solution Approach 2:
The patent employs feedback systems that continuously monitor the bearing load distribution and contact forces, then adjust the pre-loading mechanisms accordingly. This closed-loop feedback approach allows the system to self-correct uneven load profiles and maintain consistent contact forces across all rolling elements, effectively managing the complexity of the slim-profile bearing design through intelligent control
2Reliability
If high pre-loading is applied to maintain contact forces, then the contact force consistency is improved, but the design constraints and stress on bearing components increase
Solution Approach 1:
The system transitions from static high pre-loading to dynamic adaptive pre-loading. By continuously measuring the actual load profile and contact forces, the system adjusts the pre-loading forces in real-time to maintain consistent contact without applying excessive static stress. This dynamic adjustment ensures reliability while reducing unnecessary stress on bearing components
Solution Approach 2:
The patent changes the pre-loading parameters dynamically rather than maintaining fixed high pre-loading values. By adjusting the magnitude and distribution of pre-loading forces based on actual operating conditions and measured load profiles, the system maintains contact force consistency (reliability) while optimizing the stress levels to avoid excessive pre-loading stress on components
3Reliability
If bearing pre-loading is increased to avoid roller skidding, then the reliability is improved, but the wear and load variations over time increase
Solution Approach 1:
The patent implements feedback mechanisms that continuously monitor bearing condition parameters including wear indicators and load variations. This feedback enables the system to detect early signs of wear and adjust the pre-loading and load distribution accordingly, preventing conditions that would accelerate wear. The feedback loop thus extends bearing service life while maintaining the reliability needed to prevent roller skidding
Solution Approach 2:
The system employs self-adjusting mechanisms that automatically compensate for wear and load variations without external intervention. By continuously monitoring its own state and adjusting pre-loading forces to maintain optimal contact conditions, the bearing system serves itself to maintain reliability while minimizing wear accumulation over time, thereby extending service life
4Productivity
If individual blade pitch control is implemented to handle non-uniform wind flow, then the power generation efficiency is improved, but the control system complexity and bearing load variations increase
Solution Approach 1:
The patent uses feedback from bearing load measurements to coordinate and optimize individual blade pitch control actions. By monitoring how pitch adjustments affect bearing loads and using this information to refine control decisions, the system manages the complexity of individual blade control while maintaining power generation efficiency. The feedback ensures that pitch control actions do not create excessive or uneven bearing loads
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution effectively maintains consistent contact forces and load profiles, reducing wear and the likelihood of failure, while enabling real-time monitoring and adaptive control to prevent damage and optimize wind turbine operation.
Implementation Method 1
detecting strain at 15 to 20 positions evenly distributed around the bearing (5) by means of a fibre optic sensor
Data Source
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AI summary
A method of dynamically controlling a wind turbine having a rotor supporting a plurality of blades and a main bearing supporting the rotor, the method comprising: detecting a load profile around the circumference of the main bearing; generating a control signal based on the detected load profile; and dynamically adjusting the load profile of the main bearing using the control signal; wherein detecting the load profile comprises detecting strain at 15 to 20 positions evenly distributed around the bearing by means of a fibre optic sensor.