Fault Detection in Wind Turbine Bearings by Coupling Knowledge Graph and Machine Learning Approach

Abstract

Fault sensing in wind turbine (WT) generator bearings is essential for ensuring reliability and holding down maintenance costs. Feeding raw sensor data to machine learning (ML) model often overlooks the enveloping interdependencies between system elements. This study proposes a new hybrid method that combines the domain knowledge via knowledge graphs (KGs) and the traditional feature-based data. Incorporation of contextual relationships through construction of graph embedding methods, such as Node2Vec, can capture meaningful information, such as the relationships among key parameters (e.g. wind speed, rotor Revolutions Per Minute (RPM), and temperature) in the enriched feature representations. These node embeddings, when augmented with the original data, can be used to allow the model to learn and generalize better. As shown in results achieved on experimental data, the augmented ML model (with KG) is much better at predicting with the help of accuracy and error measure compared to traditional ML methods. Paired t-test analysis proves the statistical validity of this improvement. Moreover, graph-based feature importance increases the interpretability of the model and helps to uncover the structurally significant variables that are otherwise ignored by the common methods. The approach provides an excellent, knowledge-guided manner through which intelligent fault detection can be executed on WT systems.

Conflict of Interest Statement

The authors declare no conflicts of interest.