Data-driven Fault Diagnosis of Power Transformers using Dissolved Gas Analysis (DGA)

Abstract

A power transformer is a critical piece of equipment in a power plant for distributing electricity, and it experiences thermal and electrical stresses during operation. Dissolved gas analysis (DGA) remains one of the most effective techniques to monitor the health of oil-filled transformers. Some traditional approaches for interpreting DGAs have been introduced. Occasionally, such approaches leave the state of the transformer uncategorized. This study proposed data-driven approaches for a fault diagnosis system based on DGA data using support vector machine (SVM). SVM is known for its robustness, good generalization capability, and unique global optimum solutions, particularly when data is limited. Backpropagation neural networks (BPNN) and extreme learning machine-radial basis function (ELM-RBF), a recent Neural Networks (NN)-based method with extremely fast computation time, were compared to SVM. An advanced technique to overcome the imbalanced data and synthetic minority oversampling technique (SMOTE) was proposed to investigate the effect on classifier performance. The model was trained and tested using IEC TC 10 databases and transformer DGA monitoring data of a thermal power plant in Jakarta. The results indicated that SVM displayed the best performance compared to ELM-RBF and BPNN. It demonstrated extremely high accuracy, while still maintaining fast computation time for all stages in the proposed multistage fault diagnosis system.

Keywords

• condition monitoring
• dissolved gas analysis
• fault diagnosis
• support vector machine
• transformer