Wind Turbine Blade Misposition Detection Through Azimuthal Movement
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Solution Overview
Problem
Existing wind power installations face challenges in accurately determining blade mispositions due to incorrect blade angle encoders, leading to inconsistent blade loads and resulting in tower vibrations or power variations, which current measurement methods like tachymeters and gyroscopes fail to account for mass imbalances effectively.
Innovation Solution
A method involving the detection of azimuthal movements of the nacelle using an inactive azimuth actuator, combined with Fourier analysis and integration techniques, to determine blade mispositions by analyzing azimuthal movements at specific frequencies indicative of blade angle variances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If tachymeter measurement from fixed ground position is used to determine blade misposition, then absolute blade angle adjustment can be achieved, but equipment outlay becomes high
Solution Approach 1:
The wind power installation itself serves as the measurement system by utilizing its own azimuthal movements and operational data to detect blade mispositions, eliminating the need for external tachymeter equipment. The system uses its inherent operational characteristics (azimuthal movements, power curve deviations) to self-diagnose blade angle errors.
Solution Approach 2:
The patent replaces the mechanical tachymeter measurement system with an operational analysis approach using sensor data from the wind turbine's own control systems. Instead of mechanical angle measurement from ground position, the system uses azimuthal movement data and power curve analysis to infer blade mispositions.
2Ease of operation
If blade angle encoder is used to control blade position, then blade angle adjustment is enabled, but measurement accuracy deteriorates due to incorrect encoder zero position
Solution Approach 1:
The system uses feedback from operational characteristics (azimuthal movements, power output variations) to detect and identify encoder zero position errors. By monitoring how the turbine responds to azimuthal movements and comparing actual power output with expected power curves, the system can infer whether blade angles are incorrectly positioned due to encoder errors.
Solution Approach 2:
The patent performs additional operational analysis beyond standard control functions. By analyzing azimuthal movements and power curve deviations in detail, the system extracts information about blade mispositions that goes beyond the basic blade angle control function, enabling detection of encoder errors without requiring perfect encoder accuracy.
3Measurement precision
If acceleration sensors or gyroscopes are used to measure tower vibrations, then blade angle misposition detection is enabled, but mass imbalances cannot be distinguished from blade angle mispositions
Solution Approach 1:
The patent segments the analysis into different operational domains: azimuthal movement analysis for detecting blade angle mispositions, and power curve/rotation speed analysis for detecting mass imbalances. By separating these diagnostic functions into different analytical approaches using the same sensor data, the system can distinguish between different types of anomalies without requiring additional sensors.
Data Source
AI summary
A method for determining at least one blade misposition of a rotor blade of a rotor of a wind power installation having multiple rotor blades with an adjustable blade angle, wherein the blade misposition describes a blade angle variance of the blade angle of the rotor blade from a reference blade angle, the wind power installation has a nacelle having the rotor and an azimuth adjustment device, wherein a circumferential rotational position of the rotor is referred to as the rotor position, and the azimuth adjustment device has at least one activable azimuth actuator in order to adjust an azimuthal position of the nacelle, comprises the steps of a detection step comprising detecting an azimuthal movement of the nacelle while the at least one azimuth actuator is inactive, and a determination step comprising determining the blade misposition on the basis of the azimuthal movement detected in the detection step.