Tower Flange Suspended Weights for Wind Turbine Eigenfrequency Tuning
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Solution Overview
Problem
Wind turbines face operational instability due to insufficient separation between excitation frequencies and natural frequencies, leading to potential resonance conditions that can cause structural damage and safety risks, exacerbated by manufacturing and operational deviations in tower mass and foundation stiffness.
Innovation Solution
A wind turbine eigenfrequency modifier is introduced, comprising a plurality of weights suspended from a first tower flange at the upper end of the tower using rigid supports, effectively increasing the separation between natural and excitation frequencies by modifying the eigenfrequency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the tower mass and foundation stiffness are increased to improve structural stability, then the structural stability is improved, but the eigenfrequency separation between natural and excitation frequencies decreases, leading to resonance risk
Solution Approach 1:
The patent applies parameter changes by modifying the eigenfrequency of the wind turbine system through adding adjustable masses to the tower top. This changes the dynamic characteristics of the system, specifically targeting the eigenfrequency parameter to ensure sufficient separation from excitation frequencies caused by rotor harmonics, thereby preventing resonance while maintaining structural stability.
2Strength
If the tower mass is increased to improve structural integrity, then the structural integrity is improved, but the manufacturing precision and operational consistency of eigenfrequency become difficult to control
Solution Approach 1:
The patent implements dynamics by providing an adjustable mass system that can be modified after installation. The masses can be adjusted in magnitude and position to precisely tune the eigenfrequency of the wind turbine tower, allowing for post-manufacturing optimization of dynamic characteristics without requiring changes to the tower structure itself.
Solution Approach 2:
By changing the mass parameter of the tower system through adjustable weights, the eigenfrequency can be precisely controlled and tuned. This allows manufacturers to achieve the required eigenfrequency separation even with variations in tower mass and foundation stiffness, effectively compensating for manufacturing tolerances and operational deviations.
3Reliability
If the separation between natural and excitation frequencies is increased to avoid resonance, then the resonance risk is reduced, but the device complexity increases due to additional components
Solution Approach 1:
The patent applies segmentation by dividing the adjustable mass system into multiple discrete masses that can be independently adjusted. These masses are distributed at different positions on the tower top, allowing for fine-tuning of the eigenfrequency characteristics. The segmented approach provides flexibility in achieving the desired frequency separation while keeping each individual component relatively simple.
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 efficiently compensates for deviations in tower mass and foundation stiffness, reducing the risk of resonance and extending the frequency separation, thereby enhancing the structural integrity and operational stability of wind turbines.
Implementation Method 1
an eigenfrequency modifier including a plurality of weights suspended from the first tower flange by a plurality of rigid supports
Implementation Method 2
A fundamental system frequency that is driven by a harmonic rotor load is called a resonance condition. Potentially large structural displacements can result from a resonance condition. Thus, there is a problem of resonance condition in wind turbines
Data Source
AI summary
It is provided a wind turbine having a modified eigenfrequency, the wind turbine having a tower including a first tower flange arranged at an upper end portion of a top part of the tower; and, an eigenfrequency modifier including a plurality of weights suspended from the first tower flange by a plurality of rigid supports. It is further provided a method of modifying an eigenfrequency of a wind turbine, the method including modifying the eigenfrequency of the wind turbine by suspending a plurality of weights from a first tower flange arranged at an upper end portion of a top part of a tower of the wind turbine using a plurality of rigid supports.