Wind Turbine Blade Mode Control for Load Reduction
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Solution Overview
Problem
Designing wind turbine blades with active aerodynamic devices (AADs) to maximize performance and control turbulence-induced loads is challenging, as existing methods lack efficient control methods and optimal placement strategies for AADs.
Innovation Solution
A method that identifies excited mode shapes of the wind turbine blade and adjusts active lift devices based on these modes to reduce modal vibrations, using sensors to measure deflection and compare it with known mode shapes, allowing for precise control of AADs at strategic locations along the blade to minimize interference between mode shapes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If standard root moment control systems are used, then control of blade loads is achieved, but control response speed is slow
Solution Approach 1:
The control system is segmented into multiple independent mode controllers, each responsible for a specific blade mode (flapwise, edgewise, torsion). This allows parallel processing of different mode controls, significantly improving response speed while maintaining comprehensive control effectiveness for each mode.
Solution Approach 2:
The control system dynamically adapts to different operating conditions by selectively activating controllers for dominant modes. The system identifies which modes are currently excited and applies control only to those modes, optimizing response speed while maintaining control effectiveness through dynamic adjustment of control parameters.
2Measurement precision
If advanced model simulation-based control is used, then control accuracy is improved, but computational requirements increase significantly
Solution Approach 1:
The complex advanced control model is decomposed into separate, simplified mode-specific controllers. Each controller handles only one blade mode using reduced-order models, extracting the essential control function for each mode while eliminating unnecessary computational complexity. This maintains control accuracy for each mode while dramatically reducing overall computational requirements.
Solution Approach 2:
Different control strategies are applied to different blade modes based on their specific characteristics. Simple proportional controllers are used for modes where high accuracy is not critical, while more sophisticated control is applied only where needed. This local differentiation maintains necessary control accuracy while minimizing computational energy consumption across the entire system.
3Adaptability or versatility
If AADs are placed to control multiple mode shapes, then control coverage is improved, but interference between mode shapes increases
Solution Approach 1:
The blade is divided into multiple mode-specific control zones, with dedicated active aerodynamic devices assigned to control specific blade modes (flapwise, edgewise, torsion). Each device is positioned and controlled to affect primarily its designated mode, preventing interference with other modes while maintaining comprehensive control coverage across all blade dynamics.
Solution Approach 2:
The control system dynamically identifies which blade modes are currently excited and activates only the corresponding mode controllers. This dynamic selection prevents unwanted interference between modes by ensuring that control actions are applied only to the dominant mode, while maintaining the capability to control all modes as conditions change.
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 provides faster control responses, reduces fatigue loads, and decreases computational requirements, offering a more efficient method for controlling wind turbine blades by optimizing the placement and operation of AADs.
Implementation Method 1
adjusting at least one active lift device provided on said blade to reduce a modal vibration of said blade
Data Source
AI summary
A control method for a wind turbine, in particular for a wind turbine blade is described. The control method makes use of the blade mode shapes, or natural vibration shapes, of the blade to detect the excitement level of the blade natural vibrations, and controls active lift devices on the blade in an effort to reduce the excitement levels, to reduce loading in the blade and the overall wind turbine structure. There is also provided a method of designing a wind turbine blade for use in such a method.