Blade-Tower Clearance Monitoring via Acoustic Signal Sequence

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Solution Overview

Problem

Existing methods for monitoring the clearance between wind turbine blades and towers are cumbersome, affected by blade orientation and attitude, and prone to environmental interference, making them inefficient and costly.

Innovation Solution

A system comprising signal transmitters on each blade tip, symmetrically positioned first and second signal receivers on the nacelle, and a control system to determine clearance based on signal reception sequence, enabling easy installation and maintenance, and unaffected by blade deformation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If electromagnetic or mechanical waves are used to detect blade tip attitude and clearance distance, then measurement capability is provided, but the system becomes cumbersome and complicated due to uncertain blade orientation and attitude

Engineering Contradiction:
Improveclearance measurement capabilityVSAvoiddata processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical/optical detection systems with a simpler acoustic-based system. Instead of using electromagnetic or mechanical waves requiring complex image recognition and data processing, the invention uses acoustic waves transmitted through the blade structure itself, leveraging the blade as a natural waveguide to detect clearance without complicated processing

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

Solution Approach 2:

The patent introduces acoustic waves as an intermediary medium to transfer information about blade-tower clearance. The acoustic waves propagate through the blade structure and are received at the tower, providing a direct physical coupling that eliminates the need for complex optical or electromagnetic detection and processing systems

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of information

If image recognition is used to detect blade tip orientation, then clearance information can be obtained, but the process becomes cumbersome and time-consuming

Engineering Contradiction:
Improveclearance information acquisitionVSAvoiddata post-processing time
Core Design Contradiction:
Loss of informationVSLoss of time

Solution Approach 1:

The patent replaces optical image recognition systems with acoustic wave propagation through the blade structure. This substitution eliminates the need for complex image processing and reduces time loss, as acoustic waves provide direct physical information about clearance without requiring computational analysis of visual data

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

3Measurement precision

If laser devices are used to measure clearance, then measurement is possible, but results are easily affected by dust, smog, and environmental factors

Engineering Contradiction:
Improveclearance measurement accuracyVSAvoidenvironmental interference
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent replaces optical laser measurement systems with acoustic wave propagation through the blade structure. Acoustic waves are less susceptible to environmental interference from dust and smog compared to optical waves, providing more reliable measurements in challenging environmental conditions

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

Solution Approach 2:

The patent uses acoustic waves as an intermediary that can penetrate through the blade structure and propagate to the tower despite environmental obstacles. This acoustic intermediary is less affected by dust and smog than optical lasers, maintaining measurement accuracy in polluted environments

Inventive Principle:
Principle #24Intermediary (Mediator)

4Measurement precision

If detection devices are installed on the tower, then clearance monitoring is possible, but installation and maintenance become inconvenient

Engineering Contradiction:
Improveclearance monitoring capabilityVSAvoidinstallation and maintenance convenience
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent segments the detection system into distributed components: acoustic transmitters are placed at multiple locations along the blade, and receivers are positioned at the tower. This segmentation allows for easier installation and maintenance compared to centralized systems, as individual components can be accessed and serviced independently

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs a self-service monitoring approach where the blade structure itself acts as the waveguide and detection medium. The system uses the blade's own structural properties to transmit acoustic waves, eliminating the need for complex external detection devices on the tower and simplifying installation and maintenance

Inventive Principle:
Principle #25Self-service

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

Effectively monitors blade-tower clearance to prevent tower sweeping, reducing the need for complex data processing and environmental interference, with efficient, reliable, and cost-effective performance.

Implementation Method 1

transmitting, by a signal transmitter, a signal

Methodology Applied
Scientific EffectAcoustic wave transmission: Sound

Data Source

PatentEP4198303B1Monitoring device and method for clearance of blades of wind turbine generator set, and wind turbine generator set
Publication Date: 2025.06.25 SHANGHAI ELECTRIC WIND POWER GRP CO LTD
  • EP4198303B1 patent drawingFigure 1
  • EP4198303B1 patent drawingFigure 2
  • EP4198303B1 patent drawingFigure 3

AI summary

An apparatus (200) for monitoring a clearance of a blade (104) of a wind turbine (100). The apparatus (200) includes: a signal transmitter (201) provided on each blade (104); a first signal receiver (202) and a second signal receiver (203) provided on a nacelle (102); and a control system (204) communicatively connected with the first signal receiver (202) and the second signal receiver (203). The signal transmitter (201) is installed at the top of a blade tip of the blade (104). The wind turbine (100) has a safety clearance plane (S), the safety clearance plane (S) being a plane which is located at a safety clearance position between the blade tip and a tower (101) and is parallel to an axis (L) of the tower (101), where the first signal receiver (202) and the second signal receiver (203) are arranged symmetrically with respect to the safety clearance plane (S). The control system (204) determines whether there is a risk of tower sweeping, based on a sequence in which the first signal receiver (202) and the second signal receiver (203) receive a signal transmitted by the signal transmitter (201). Further disclosed are a method of monitoring a clearance of a blade (104) of a wind turbine (100), and a wind turbine (100). The apparatus (200) can simply, conveniently and effectively monitor the clearance between the blade (104) and the tower (101), so as to prevent tower sweeping.