Wind Turbine Rotor Blade Position Monitoring via Gravity Moments

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Solution Overview

Problem

Wind turbine rotor blades face challenges in maintaining accurate rotational position and order during maintenance and repair, leading to potential misalignment and damage due to environmental factors and component failures, necessitating independent monitoring of their rotational positions.

Innovation Solution

A method utilizing gravity-induced blade moments measured by sensors, such as strain gauges, to determine the rotational position of rotor blades by analyzing the sinusoidal behavior of these moments during idle rotations, allowing for precise identification and ordering of blades.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of repair

If rotor blades are exchanged during maintenance and repair, then maintenance and repair work can be performed, but the individual position and order of rotor blades may be changed leading to misalignment

Engineering Contradiction:
Improvemaintenance and repair workVSAvoidrotor blade position accuracy
Core Design Contradiction:
Ease of repairVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by marking rotor blades with unique identification markers and recording their original positions before maintenance activities. This allows the system to pre-calculate and monitor expected position changes, enabling verification of correct reinstallation and detection of any misalignment or wrong ordering of blades during subsequent operations.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If individual rotor blades are monitored independently, then accurate rotational position and blade order can be determined, but the complexity of the measurement system increases

Engineering Contradiction:
Improverotational position determination accuracyVSAvoidmeasurement system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies self-service by utilizing the rotor blade's own gravitational force and moment of inertia as natural measurement signals. The system evaluates the gravitational moment acting on each marked rotor blade during rotation, allowing the blades themselves to generate the measurement signals needed for position determination without requiring additional active sensors or complex measurement equipment on each blade.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces complex mechanical position sensing systems with a gravitational moment evaluation approach. Instead of using encoders, resolvers, or other active mechanical sensors on each rotor blade, the system uses strain gauges or force sensors on the hub to measure the gravitational moment, which is then processed to determine blade positions and order, significantly reducing system complexity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If environmental factors and component failures are considered, then rotor blade damage risk increases, but independent monitoring can reduce misalignment and damage

Engineering Contradiction:
Improveoperational safetyVSAvoidenvironmental factors and component failures
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies feedback by continuously monitoring the gravitational moment of each rotor blade during operation and comparing it with expected values based on the recorded blade order and positions. When deviations are detected indicating misalignment, wrong ordering, or potential damage, the system generates alerts or shutdown signals, providing real-time feedback to prevent further damage and ensure operational safety.

Inventive Principle:
Principle #23Feedback

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 accurate monitoring and maintenance of rotor blade positions, reducing the risk of misalignment and damage by providing a reliable method for determining the rotational position and order of individual blades, enhancing operational efficiency and safety.

Implementation Method 1

a first gravity induced blade moment of the rotor blade is measured at an arbitrary first rotational position of the rotor blade. Furthermore, at least one second gravity induced blade moment of the rotor blade is measured at at least a second rotational position of the rotor blade

Methodology Applied
Scientific EffectGravitation: Gravitation

Implementation Method 2

A method utilizing gravity-induced blade moments measured by sensors, such as strain gauges, to determine the rotational position of rotor blades

Methodology Applied
Scientific EffectStrain gauge measurement: Piezoresistive Effect

Data Source

PatentEP2381098B1Method for measuring a rotational position of a rotor blade of a wind turbine and measuring device
Publication Date: 2017.06.14 GENERAL ELECTRIC CO
  • EP2381098B1 patent drawingFigure 1
  • EP2381098B1 patent drawingFigure 2
  • EP2381098B1 patent drawingFigure 3

AI summary

The present disclosure is related to a method and a measuring device adapted for determining a rotational position of at least one rotor blade (1010, 1011, 1012) of a wind turbine (100). The method includes a step of measuring a gravity induced blade moment of the at least one rotor blade (1010, 1011, 1012. Then, an actual rotational position of the rotor blade (1010, 1011, 1012) is determined from the measured gravity induced blade moment.