Wind Turbine Tower Strike Prediction Using Blade and Tower Bending Sensors
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Solution Overview
Problem
Existing wind turbine systems for identifying the likelihood of a tower strike are inadequate due to reliance on blade bending measurements alone, which do not account for tower flexibility and provide insufficient warning time for evasive action, and are prone to failure in harsh environments.
Innovation Solution
A system that senses both rotor blade and tower bending using Long Period Grating sensors to accurately determine the distance between the blade and tower, enabling predictive identification of potential strikes and allowing for timely evasive action, while also allowing for the use of lighter, more flexible towers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If only blade bending measurements are used to identify tower strike likelihood, then the system is simpler, but the prediction accuracy is insufficient and warning time is inadequate
Solution Approach 1:
The patent combines blade bending sensors and tower bending sensors into a unified monitoring system. The processor integrates data from both sensor types to compute real-time clearance distances between blades and tower, achieving accurate tower strike prediction by merging multiple measurement sources rather than relying on blade bending alone.
Solution Approach 2:
The processor acts as an intermediary that receives raw data from both blade and tower bending sensors, processes this information through computational algorithms, and generates predictive clearance measurements. This intermediary processing layer transforms individual sensor measurements into actionable safety predictions.
2Weight of stationary object
If tower metal content is reduced to make towers lighter and cheaper, then transportation and installation become easier, but tower flexibility increases and tower strike risk increases
Solution Approach 1:
The system implements continuous feedback by monitoring both blade and tower bending in real-time. The processor uses this feedback to dynamically calculate clearance distances and predict potential tower strikes, enabling the lighter tower design to operate safely within monitored parameters.
Solution Approach 2:
The system performs preliminary detection of tower strike conditions by analyzing bending trends before actual contact occurs. By identifying approaching clearance thresholds in advance, the system allows evasive action to be taken before a strike happens, making lighter towers safe through early warning capability.
3Reliability
If larger safety margins are used in tower strike prediction, then safety is improved, but the wind turbine operates at lower power output for longer periods
Solution Approach 1:
The patent applies partial monitoring action by focusing sensors on critical measurement points (specific blade and tower locations experiencing maximum bending). This targeted approach provides sufficient safety information without requiring excessive measurement coverage, enabling tighter safety margins with adequate protection.
Solution Approach 2:
The system dynamically adjusts operational decisions based on real-time bending measurements and predicted clearance. Rather than using fixed conservative margins, the processor continuously updates clearance predictions, allowing the turbine to operate closer to maximum power output when conditions are safe while maintaining safety when risks are detected.
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 approach enhances the accuracy of tower strike prediction, reduces the need for excessive safety margins, and allows wind turbines to operate closer to maximum power output, while maintaining safety and reducing maintenance costs by using fewer sensors to measure tower bending in multiple dimensions.
Implementation Method 1
The devices for sensing bending of the rotor blade and the tower comprise a sensor arranged at the blade and tower for outputting a signal indicative of blade and tower bending
Data Source
AI summary
A system for identifying the likelihood of a wind turbine rotor blade striking a wind turbine tower comprises a device for sensing bending of a wind turbine rotor blade and a device for sensing bending of a wind turbine tower. In a preferred embodiment Long Period Grating (LPG) sensors are used to measure bending of the tower. Preferably a plurality of LPG sensors is provided along the length of the blade. In one embodiment at least one of the LPG sensors comprises two sensing elements arranged to sense in perpendicular directions. In another embodiment a plurality of LPG sensors are provided each on different sides of the wind turbine tower. A processor uses the sensed blade and tower bending to determine whether the distance between the blade and the tower will be below a predetermined minimum value. If the distance is determined to be below the predetermined minimum value a controller may be used to adjust a wind turbine variable to reduce loading on the blade and thereby reduce the likelihood of a tower strike.