Wind Turbine Control Using Multi-Axial Accelerometers
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Solution Overview
Problem
Current methods for controlling wind turbines are limited in accurately determining tower oscillations and thrust forces, leading to suboptimal power extraction and increased loads, as they primarily focus on fore-aft motion and rely on thrust estimates, which decrease accuracy.
Innovation Solution
The use of multiple multi-axial accelerometers at various positions on the nacelle and tower to measure accelerations in multiple directions, including gravity components, allowing for precise determination of absolute positions and velocities, and estimation of thrust forces through pre-determined mode shapes and Kalman filtering, enabling more accurate control of tower oscillations and load management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single accelerometer is used to measure fore-aft accelerations of the nacelle, then the measurement setup is simple, but the accuracy of tower top position determination is insufficient and side-side motion is not captured
Solution Approach 1:
The patent transitions from single-axis accelerometer measurement to multi-axial accelerometer measurement, adding measurement dimensions to capture both fore-aft and side-side tower motions simultaneously. This dimensional expansion enables comprehensive 3D motion characterization without proportionally increasing system complexity
Solution Approach 2:
The patent divides the measurement function across multiple accelerometers positioned at different locations (nacelle and tower top), with each sensor contributing specific motion components. This segmentation allows comprehensive tower motion analysis while maintaining manageable device complexity
2Measurement precision
If thrust force estimates are used in the estimation method, then the system requires fewer direct measurements, but the accuracy of the method decreases
Solution Approach 1:
The patent implements feedback by using measured accelerations from multi-axial accelerometers to continuously update and refine thrust force estimates. The measured tower responses are fed back into the estimation algorithm, creating a closed-loop system that improves accuracy over time rather than relying on open-loop thrust estimates
Solution Approach 2:
The patent replaces direct mechanical thrust measurement instruments with accelerometer-based indirect measurement. By substituting complex thrust measurement hardware with simpler accelerometers and computational estimation, the system achieves comparable or superior accuracy while reducing device complexity
3Loss of information
If only fore-aft motion is taken into account, then the control system is simpler, but the completeness of tower oscillation characterization is insufficient
Solution Approach 1:
The patent makes the control system universal by enabling it to handle both fore-aft and side-side tower motions through multi-axial accelerometer measurement. The same measurement and control infrastructure serves multiple motion directions simultaneously, preventing information loss without proportionally increasing complexity
Solution Approach 2:
The patent transitions from static, single-direction control to dynamic, multi-directional control by continuously measuring and responding to tower motions in both fore-aft and side-side directions. This dynamic adaptation ensures complete oscillation characterization while maintaining manageable control system complexity
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 a more precise and robust method for controlling wind turbines, improving the accuracy of tower position and velocity estimation, and thrust force determination, leading to better oscillation damping and load management, enhancing power extraction and reducing structural stress.
Implementation Method 1
a plurality of multi-axial accelerometers mounted at different positions in the nacelle and/or in a top portion of the tower, each accelerometer being mounted in a defined orientation
Implementation Method 2
the accelerometers will measure components of both the actual accelerations from the tower top movements as well as from the gravity
Data Source
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AI summary
The invention relates to control of a wind turbine comprising a plurality of multi-axial accelerometers mounted at different positions in the nacelle and/or in a top portion of the tower. The position and orientation of each accelerometer as mounted is obtained, accelerations in at least two different directions by each accelerometer are measured during operation of the wind turbine. From a number of pre-determined mode shapes for the movement of the wind turbine is then determined an absolute position of at least one of the accelerometers during operation of the wind turbine based on the measured accelerations, the mount position and orientation of each accelerometer and the pre-determined mode shapes. Hereby a more precise absolute position during operation is obtained which can be used in the controlling of the turbine.