Wind Turbine Bearing Fault Detection via Frequency Segmentation

Solution Overview

Problem

Current methods for detecting failures in wind turbine shafts, particularly low-energy faults, are unreliable and unsuitable for slow-speed bearings, as they struggle to differentiate between ambient noise and fault signals due to variability in characteristic frequencies.

Innovation Solution

A method involving the measurement of a physical quantity representative of the wind turbine's movement, transformation into a frequency signal, calculation of a transformed spectrum, and verification of detection criteria to identify faults through enhanced frequency resolution and spectrum cleaning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If frequency resolution is increased to differentiate fault signals from ambient noise, then measurement precision improves, but phantom components appear and reliability deteriorates

Engineering Contradiction:
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent applies preliminary action by calculating the characteristic frequency of the bearing defect before performing spectrum analysis. This allows the system to pre-identify the frequency range of interest and apply targeted filtering or enhancement only in that range, avoiding the need to increase overall frequency resolution which would introduce phantom components. The characteristic frequency is calculated based on bearing geometry and operating conditions, enabling focused detection without global resolution increases.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If characteristic frequency accuracy is increased to improve fault detection, then measurement precision improves, but device complexity increases due to contact angle variability

Engineering Contradiction:
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces an intermediary approach by using measured vibration signals to empirically determine characteristic frequencies rather than relying solely on theoretical calculations that require precise contact angle measurements. The system uses signal processing techniques to identify actual operating frequencies from the vibration data itself, acting as an intermediary between theoretical models and actual fault detection. This avoids the complexity of directly measuring or calculating contact angles while still achieving accurate frequency identification.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If vibration analysis uses global indicators like RMS or kurtosis, then ease of operation improves, but measurement precision deteriorates for low-energy faults

Engineering Contradiction:
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent applies segmentation by dividing the vibration spectrum into multiple frequency bands or channels, each centered on characteristic defect frequencies and their harmonics. Instead of using a single global indicator, the system calculates separate indicators for each frequency channel, allowing sensitive detection of low-energy faults in specific frequency ranges while maintaining operational simplicity. This segmented approach enables targeted monitoring of bearing defect frequencies without requiring complex multi-parameter analysis.

Inventive Principle:
Principle #1Segmentation

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 detection of low-energy faults in wind turbine bearings by improving frequency resolution and distinguishing between harmonics, effectively identifying faults before they escalate.

Implementation Method 1

a vibration sensor, in particular a piezoelectric sensor, arranged to be attached to the shaft

Methodology Applied
Scientific EffectVibration: Vibration

Implementation Method 2

The measured time signal is transformed in a frequency domain by applying a Fourier transform to the measured time signal

Methodology Applied
Scientific EffectFourier transform:

Data Source

PatentEP3535491B1Method for detecting the failure of a moving component of a wind turbine
Publication Date: 2023.02.15
  • EP3535491B1 patent drawingFigure 1~3
  • EP3535491B1 patent drawingFigure 4~10
  • EP3535491B1 patent drawingFigure 11

AI summary

The present invention relates to a method for detecting the failure of a moving component of a wind turbine. The detection method comprises measurement, transformation and spectrum calculation steps, allowing the fulfillment of a detection criterion to be verified.