Wind Turbine Blade Stress Sensing With Radar Motion Analysis
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Solution Overview
Problem
Conventional methods for measuring stress and load on wind turbine blades are not reliable and fast enough, leading to potential structural damage and wear, and there is a need for a method to accurately and quickly determine stress and load on these blades to keep within acceptable limits.
Innovation Solution
A method using a radar system to emit a primary radar signal towards a rotor blade, receive a secondary radar signal, and analyze it to derive stress-related quantities such as blade acceleration and its derivatives, enabling accurate and fast stress measurement and control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional methods (strain gauges, radar units) are used to measure stress and load on rotor blades, then measurement capability is provided, but measurement reliability and speed are insufficient
Solution Approach 1:
The patent replaces conventional mechanical measurement systems (strain gauges, traditional radar units) with a radar-based measurement system that uses electromagnetic waves to detect blade motion and calculate stress-related quantities. This substitution enables faster and more reliable measurements by utilizing the high speed of light and advanced signal processing techniques.
Solution Approach 2:
The patent changes the measurement parameter from direct stress measurement to measurement of blade motion parameters (position, velocity, acceleration) through radar signal analysis. By measuring the motion parameters and deriving stress-related quantities from them, the system achieves both high reliability and speed in measurement.
2Strength
If stress measurement is performed to prevent structural damage and wear, then blade protection is achieved, but measurement accuracy and speed are insufficient
Solution Approach 1:
The patent implements a feedback mechanism where radar-measured blade motion data is continuously analyzed to determine stress-related quantities, which are then used to control blade pitching operations. This closed-loop feedback system ensures accurate and timely stress measurement for protecting blade structural integrity.
Solution Approach 2:
The system performs preliminary measurement of blade motion parameters through radar detection before actual stress damage occurs. By measuring position, velocity, and acceleration early in the loading process, the system can predict stress states and take preventive actions to protect blade strength.
3Productivity
If radar signal analysis is used to determine stress-related quantities, then measurement speed and reliability are improved, but system complexity increases
Solution Approach 1:
The patent makes the radar system multi-functional by using it not only for stress measurement but also for blade position detection, velocity measurement, and acceleration calculation. This universal approach reduces overall system complexity despite the advanced signal processing required, as a single radar system performs multiple measurement functions.
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
Enables reliable and rapid determination of stress and load on wind turbine blades, allowing for effective control to keep them within acceptable limits, reducing wear and tear, and improving performance and component lifetime.
Implementation Method 1
emitting a primary radar signal towards a portion of the blade; receiving a secondary radar signal emanating from the blade due to interaction with the primary radar signal
Implementation Method 2
analyzing at least the received secondary radar signal; and deriving, based on the analysis, the value of the stress related quantity as related to or indicating a blade acceleration
Data Source
AI summary
A method of determining a value of a stress related quantity of a rotor blade of a wind turbine is provided, the method including: emitting a primary radar signal towards a portion of the blade; receiving a secondary radar signal emanating from the blade due to interaction with the primary radar signal; analyzing at least the received secondary radar signal; and deriving, based on the analysis, the value of the stress related quantity as related to or indicating a blade acceleration and/or a first temporal derivative of the blade acceleration and/or a higher temporal derivative of the blade acceleration.