Tower Flange Suspended Weights for Wind Turbine Resonance Margin

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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

VSEngineering Contradiction Analysis

1Reliability

If the wind turbine operates with standard tower mass and foundation stiffness, then the structure is simple and cost-effective, but the separation between excitation frequencies and natural frequencies is insufficient leading to resonance risk

Engineering Contradiction:
Improveoperational stabilityVSAvoidtower structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by modifying the tower's mass distribution through add-on mass elements. These elements change the physical parameters of the tower system, specifically increasing the separation between excitation frequencies and natural frequencies to prevent resonance. The mass elements are configured with specific masses and positions to achieve the desired frequency separation while maintaining structural integrity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces another dimension by adding mass elements in the vertical and radial dimensions of the tower. The add-on mass elements are positioned at specific heights and radial distances from the tower axis, creating a three-dimensional mass distribution that modifies the tower's vibrational characteristics without requiring complete redesign of the tower structure.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If manufacturing and operational deviations occur in tower mass and foundation stiffness, then the wind turbine may experience resonance conditions, but redesigning the entire tower is costly and complex

Engineering Contradiction:
Improveresonance preventionVSAvoidmodification process
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies segmentation by dividing the mass modification into separate, modular add-on mass elements. These elements can be independently manufactured, positioned, and attached to the tower at different locations. This segmentation allows for flexible configuration to compensate for various manufacturing and operational deviations without requiring complete tower redesign.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies preliminary action by pre-calculating and pre-configuring the add-on mass elements with specific masses and positions that will achieve the desired frequency separation. The elements are designed in advance to compensate for expected deviations in tower mass and foundation stiffness, allowing for straightforward installation without complex on-site adjustments.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If weights are suspended from the tower flange, then the eigenfrequency is modified to increase frequency separation, but additional components and installation complexity are introduced

Engineering Contradiction:
Improvefrequency separationVSAvoideigenfrequency modifier
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies universality by designing add-on mass elements that serve multiple functions: they modify the tower's eigenfrequency, provide ballast for stability, and can be configured to compensate for various mass deviations. The same basic element design can be used in different configurations (different masses, positions, and numbers) to address different operational requirements, reducing the need for multiple specialized components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 ensuring a safer operational margin by increasing the frequency separation, thus preventing structural damage and enhancing the reliability of wind turbines.

Implementation Method 1

modifying an eigenfrequency of a 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

Methodology Applied
Scientific EffectEigenfrequency modification: Resonance

Implementation Method 2

suspending a plurality of weights from a first tower flange

Methodology Applied
Scientific EffectGravitational force: Gravitation

Data Source

PatentEP4086459A1Wind turbine having eigenfrequency modifier
Publication Date: 2022.11.09 GENERAL ELECTRIC RENOVABLES ESPANA SL
  • EP4086459A1 patent drawingFigure 1
  • EP4086459A1 patent drawingFigure 2
  • EP4086459A1 patent drawingFigure 3

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.