Residual Life Assessment of Oil-Immersed Insulating Paper by FTIR Feature Interpretability Evolution

The ageing of insulating paper escalates the peril of insulation failure in oil-impregnated-paper power equipment. Consequently, the real-time monitoring and non-destructive assessment of insulating paper condition assume paramount significance. This paper proposes a residual life prediction method of insulating paper based on Fourier transform infrared (FTIR) spectroscopy. The windowed wave feature (WWF) extraction method is designed and the WWF-bagging model is established to assess the tensile strength (TS) of insulating paper. Combined with the shapley additive explanations (SHAP) algorithm, we propose that kurtosis and skewness of infrared spectrum are the pivotal parameters for insulating paper life prediction. Additionally, a consistent correlation is observed between the infrared spectral band of aldehyde band and the ageing time. The experimental results evince that the proposed model surpasses classical methods evaluating the residual life of ageing insulating paper.