Wind Turbine Nonlinear Blade Control for Structural Fatigue Reduction
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Solution Overview
Problem
Current wind turbine control systems are limited by their inability to effectively account for mechanical impacts such as fatigue and extreme moments, especially at high wind speeds, due to their linear control methods which do not adequately address the nonlinear characteristics of wind turbines.
Innovation Solution
A method for optimizing electrical energy production in horizontal axis wind turbines through nonlinear control of blade orientation, using a physical model of aerodynamic forces to minimize mechanical impact by adjusting blade angles to zero speed conditions, incorporating terms proportional to wind speed and torsion to reduce speed variations and fatigue.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If linear control methods are used for power regulation by controlling blade pitch angle, then the control system is simple to implement, but the performance is limited by the highly nonlinear characteristics of the wind turbine
Solution Approach 1:
The patent transitions from linear control parameters to nonlinear control parameters by implementing a nonlinear observer that estimates states based on nonlinear system dynamics. This allows the control system to adapt to the highly nonlinear characteristics of wind turbines while maintaining reasonable complexity through systematic estimation approaches.
Solution Approach 2:
The patent replaces direct mechanical measurement systems with a nonlinear observer-based estimation system. Instead of using complex mechanical sensors and direct measurement devices, the system uses mathematical models and observers to estimate states, reducing mechanical complexity while improving performance through nonlinear modeling.
2Productivity
If wind turbines are designed to maximize efficiency at high wind speeds above 15 m/s, then energy recovery is optimized, but mechanical damage and fatigue occur on the structure
Solution Approach 1:
The patent implements feedback control through a nonlinear observer that continuously estimates system states and feeds this information back to the control mechanism. This feedback loop allows real-time adjustment of blade pitch angles to balance energy recovery with structural protection, preventing excessive mechanical damage while maintaining efficiency.
Solution Approach 2:
The patent employs dynamic control strategies that adapt to changing wind conditions in real-time. The nonlinear observer and control system dynamically adjust blade orientation based on current operational states, enabling the turbine to optimize energy recovery at varying wind speeds while dynamically managing mechanical loads to protect structural integrity.
3Productivity
If existing nonlinear control strategies are implemented, then control performance improves, but mechanical impact (fatigue and extreme moment) on the structure is not minimized
Solution Approach 1:
The patent applies preliminary action by using the nonlinear observer to predict and estimate future system states before they fully manifest. This allows the control system to take preventive measures by adjusting blade pitch angles in advance, reducing mechanical impact and fatigue on the structure before extreme conditions occur, while maintaining high control performance.
Solution Approach 2:
The patent implements preliminary anti-action by using the nonlinear observer to anticipate harmful mechanical impacts and applying counteracting control actions in advance. The system predicts potential extreme moments and fatigue conditions, then adjusts blade orientation proactively to counteract these harmful effects before they fully develop, protecting the structure while maintaining control performance.
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 enhances energy production while minimizing mechanical stress and fatigue, ensuring efficient operation and extended lifespan of wind turbine components by dynamically adjusting blade angles based on real-time wind and structural data.
Implementation Method 1
A rotor, made up of several blades (usually three) and the nose of the wind turbine, fixed to the nacelle. The rotor is driven by the energy of the wind
Implementation Method 2
connected by a mechanical shaft directly or indirectly (via a gearbox and mechanical shaft system) to the electrical machine (electric generator...) which converts the energy collected into electrical energy
Data Source
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AI summary
The method involves determining aerodynamic force produced on a nacelle when blades are oriented at first inclination angle. A first setpoint value of the aerodynamic force produced on the nacelle when the blades are oriented at the first inclination angle is determined. A second inclination angle of the blades is determined to obtain a second setpoint value of aerodynamic force by reversing an aerodynamic force model and using wind speed measurement, rotor speed measurement and the first aerodynamic force setpoint value. The blades are oriented according to the second inclination angle.