Wind Turbine Blade Load Calibration via Distortion Sensors

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Solution Overview

Problem

The existing methods for calibrating load on wind turbine blades are inefficient due to the need for manual fixing of wind turbine rotors and repeated calibration across varying conditions, leading to high work time and low efficiency, especially in large-scale wind farms.

Innovation Solution

A load measuring apparatus that includes sensors to measure blade distortion, a load calculating function, and a calibration mechanism that adjusts the function based on measurement data within specific pitch angle and rotational speed ranges where aerodynamic torque variations are minimal, allowing for efficient calibration regardless of observation conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If manual fixing of wind turbine rotors is performed for calibration, then calibration accuracy can be achieved, but enormous work time is required and work efficiency is low

Engineering Contradiction:
Improvecalibration accuracyVSAvoidwork time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The wind turbine performs self-calibration by utilizing its own operational data (distortion measurements and calculated loads) without requiring external manual intervention. The calibration function uses the turbine's own sensor data collected during normal operation to automatically adjust calibration parameters, eliminating the need for manual rotor fixing and external calibration equipment.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system collects and stores distortion measurement data and load calculation data during normal operation before calibration is needed. By accumulating this operational data in advance, the system prepares the necessary calibration information without requiring separate calibration operations, thus reducing calibration time while maintaining accuracy.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If repeated calibration is performed on each wind turbine blade, then accurate load measurement is achieved, but the work is not performed smoothly and efficiency is low

Engineering Contradiction:
Improveload measurement accuracyVSAvoidwork efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The calibration function serves multiple wind turbine blades simultaneously using a single centralized processing system. The load calculating unit processes data from multiple blades and performs calibration for all blades through one unified function, eliminating the need to repeatedly position and calibrate each blade individually while maintaining accurate load measurement for each blade.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Measurement precision

If manual positioning of blades to predetermined angles is performed, then calibration conditions are met, but it takes long time and work efficiency is reduced

Engineering Contradiction:
Improvecalibration condition accuracyVSAvoidpositioning time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system transitions from static calibration at fixed predetermined angles to dynamic calibration using operational data collected across various pitch angles and rotational speeds during normal turbine operation. The calibration function processes data from dynamic operating conditions rather than requiring the turbine to be positioned at specific static angles, thereby eliminating positioning time while maintaining calibration accuracy.

Inventive Principle:
Principle #15Dynamics

4Reliability

If calibration is performed in limited pitch angle and rotational speed ranges, then aerodynamic torque variation is minimized, but observation conditions are restricted

Engineering Contradiction:
Improveaerodynamic torque stabilityVSAvoidobservation condition range
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The system changes the calibration approach from requiring specific pitch angle and rotational speed parameter ranges to using a broad range of operational parameters. By collecting data during normal operation across various pitch angles and rotational speeds, and using the calibration function to process this diverse data set, the system expands observable conditions while maintaining reliability through mathematical processing that accounts for aerodynamic torque variations.

Inventive Principle:
Principle #35Parameter changes

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 enables precise and efficient calibration of wind turbine blade loads, reducing the time and effort required for calibration and improving work efficiency by using measurement data from defined aerodynamic torque conditions.

Implementation Method 1

a sensor (7) for obtaining a distortion of the wind turbine blade

Methodology Applied
Scientific EffectDistortion measurement: Deformation

Data Source

PatentEP2431607B1Load measuring device, method and program
Publication Date: 2016.05.25 MHI VESTAS OFFSHORE WIND AS
  • EP2431607B1 patent drawingFigure 1
  • EP2431607B1 patent drawingFigure 2~3
  • EP2431607B1 patent drawingFigure 4

AI summary

An object of the invention is to calibrate a load based on data collected under wide observation conditions and promptly calibrate loads of a plurality of wind turbine blades. There is provided a load measuring apparatus 1 applied to a wind turbine in which a pitch angle of a wind turbine blade 10 is variable, the apparatus including: a sensor for obtaining a distortion of the wind turbine blade 10; a load calculating unit 20 having a function expressing a relation between the distortion of the wind turbine blade 10 and a load on the wind turbine blade 10, for obtaining the load on the wind turbine blade 10 by applying to the function the distortion based on measurement data of the sensor; and a calibration unit 30 for calibrating the function based on the measurement data of the sensor obtained in a pitch angle range and a rotational speed range of the wind turbine blade 10 in which a variation between maximum and minimum aerodynamic torques is equal to or less than a predetermined value.