Wind Turbine Rotor Blade Angle Control During Storms

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Solution Overview

Problem

Wind turbines face high mechanical stresses during storms, especially when wind directions are unfavorable, leading to oblique currents and increased loads, which existing solutions fail to adequately mitigate.

Innovation Solution

A method for controlling wind turbines that adjusts the blade angle of rotor blades based on detected gust loads, allowing for angles beyond the traditional 90-degree flag position, using load sensors and control systems like PI and PD controllers to minimize loads, and aligning the turbine in a low-stress orientation during storms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the rotor blades are adjusted to a feathered position (90 degrees) to minimize surface area during storms, then the wind turbine is protected from wind loads, but significant stress still occurs due to oblique currents and unfavorable wind directions

Engineering Contradiction:
Improvestorm protectionVSAvoidmechanical stress
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The patent implements dynamic blade angle adjustment that allows rotor blades to deviate from the traditional fixed 90-degree feathered position. The control system continuously monitors wind conditions and adjusts blade angles individually to optimize protection against varying wind directions and gusts, transforming the static feathering concept into a dynamic load mitigation strategy

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the operational parameters of blade angle adjustment by removing the conventional 90-degree constraint. The control system permits blade angles to exceed 90 degrees and varies angles individually for each blade based on real-time wind conditions, transforming a fixed parameter approach into a flexible, condition-based parameter optimization

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If the azimuth position is adjusted to align with the wind during storms, then the wind turbine orientation is optimized, but significant stress still occurs due to varying wind directions within storms

Engineering Contradiction:
Improveazimuth alignmentVSAvoidslant wind stress
Core Design Contradiction:
Ease of operationVSForce

Solution Approach 1:

The patent segments the wind turbine control into independent blade-level adjustments rather than treating the rotor as a single unit. Each blade can be angled differently to counteract gusts from specific directions, allowing the system to handle complex, multi-directional wind patterns that affect different parts of the rotor differently

Inventive Principle:
Principle #1Segmentation

3Device complexity

If traditional feathering control with fixed 90-degree blade angles is used during storms, then the control system is simple, but it fails to account for varying wind directions and gusts

Engineering Contradiction:
Improvecontrol system simplicityVSAvoidstorm resilience
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The invention incorporates feedback mechanisms where sensors detect wind conditions including gusts from different directions, and the control system uses this information to dynamically adjust blade angles. This closed-loop control provides adaptability to varying storm conditions while maintaining manageable system complexity through sensor-based decision making

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3555462B1Method for controlling a wind turbine
Publication Date: 2024.07.31 WOBBEN PROPERTIES GMBH
  • EP3555462B1 patent drawingFigure 1
  • EP3555462B1 patent drawingFigure 2~4

AI summary

The invention relates to a method for operating a wind turbine (100), and the wind turbine (100) has an aerodynamic rotor (106) with a rotor hub and with rotor blades (202) whose blade angle can be adjusted, and the azimuth direction of the aerodynamic rotor (106) can be adjusted, and the method comprises the steps of sensing a storm situation in which the prevailing wind is so strong that for the sake of self-protection the wind turbine (100) is placed in a rotor idling mode, orienting the rotor (106) in its azimuth position into a low-load orientation with respect to the wind, in which orientation the wind turbine (100) experiences as little loading as possible by the wind from a main wind direction, sensing at least one load (LM) which is caused by a gust of wind and acts on the rotor, and adjusting the blade angle of at least one of the rotor blades (202) in such a way that the at least one rotor blade (202) experiences the lowest possible loading by the gust of wind causing the loading.