Wind Turbine Flutter Protection via Dynamic Pitch Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Wind turbines face structural instability due to flutter phenomena during high wind speeds, which existing technologies have not adequately addressed, especially in larger turbines lacking sufficient structural reinforcement.

Innovation Solution

Implementing a method that monitors wind direction and rotates rotor blades by a predetermined number of degrees from their feather position to reduce or eliminate flutter, utilizing backup energy to power control mechanisms during grid loss, and yawing the nacelle 180 degrees away from the wind direction when attack angles are detected.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If rotor blades are made larger to increase power generation capacity, then power generation efficiency is improved, but structural stability deteriorates due to increased flutter risk

Engineering Contradiction:
Improvepower generation capacityVSAvoidstructural stability
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The patent applies dynamics by making the rotor blade pitch angle adjustable rather than fixed. The control system dynamically changes the pitch angle based on real-time wind speed measurements, allowing the blade to adapt its aerodynamic properties to current operating conditions. This dynamic adjustment capability enables larger blades to operate stably across varying wind conditions without excessive flutter.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the operational parameters of the rotor blade by adjusting the pitch angle in response to wind speed thresholds. When wind speed exceeds predetermined thresholds, the system modifies the pitch angle parameter to reduce aerodynamic loading and minimize flutter. This parameter change strategy allows the blade to maintain structural stability while preserving power generation capacity under normal operating conditions.

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If structural reinforcement components are added to rotor blades to increase stiffness and strength, then structural stability is improved, but device complexity increases

Engineering Contradiction:
Improvestiffness and strengthVSAvoidstructural complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent substitutes mechanical reinforcement with aerodynamic control. Instead of adding more structural components to physically stiffen the blade, the system uses active control of the pitch angle to manage aerodynamic loads. This substitution reduces structural complexity while maintaining or improving stability through intelligent operational control rather than increased material reinforcement.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The control system enables the rotor blade to self-regulate its aerodynamic loading by automatically adjusting pitch angle in response to wind conditions. This self-service capability eliminates the need for complex external reinforcement structures, as the blade itself actively manages its own structural demands through real-time pitch adjustment based on wind speed feedback.

Inventive Principle:
Principle #25Self-service

3Stability of the object's composition

If pitch angle control system is added to reduce flutter, then structural stability is improved, but device complexity increases

Engineering Contradiction:
Improveflutter reductionVSAvoidcontrol system complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent implements feedback control by continuously measuring wind speed and using this information to adjust the rotor blade pitch angle. The control system receives real-time wind speed data, compares it against predetermined thresholds, and automatically modifies the pitch angle accordingly. This feedback mechanism provides effective flutter reduction while keeping the control logic relatively simple and rule-based rather than requiring complex predictive algorithms.

Inventive Principle:
Principle #23Feedback

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 effectively minimizes damage to wind turbines by reducing flutter and ensuring continuous operation during grid power loss through controlled pitch angle adjustments and backup energy utilization.

Implementation Method 1

The rotor blades capture kinetic energy of wind using known airfoil principles

Methodology Applied
Scientific EffectAirfoil principles: Aerofoil

Implementation Method 2

when a wind speed is above a predetermined value... the risk to the structure becomes very high, particularly when the wind turbine does not have any structural reinforcement. One such risk is flutter phenomenon, which generally refers to the dynamic instability of an elastic structure in a fluid flow

Methodology Applied
Scientific EffectFlutter: Flutter

Data Source

PatentEP3696403B1System and method for protecting wind turbines from flutter during high wind speeds
Publication Date: 2025.03.26 GENERAL ELECTRIC RENOVABLES ESPANA SL
  • EP3696403B1 patent drawingFigure 1
  • EP3696403B1 patent drawingFigure 2
  • EP3696403B1 patent drawingFigure 3

AI summary

A system and method (200) for protecting an idling wind turbine power system (10) from damage during loss of grid power. The wind turbine power system has a plurality of rotor blades (22). The method (200) includes monitoring an incoming wind direction (66) at the wind turbine power system (10). When the incoming wind direction (66) is changing at a predetermined attack angle, the method (200) also includes rotating at least one of the rotor blades of the wind turbine power system to a pitch angle that is offset from a feather position by a predetermined number of degrees to reduce and/or eliminate flutter phenomenon from occurring.