IEEE Industry Applications Magazine, 2026 (SCI-Expanded, Scopus)
The electric motor (EM) is one of the most significant electrical components used in any industrial environment. For a reliable operation of EM, it is essential to assess the health state of the stator insulation. Partial discharge (PD) diagnostics stand out as a reliable approach for evaluating the health of insulation material. During industrial operations, EMs are exposed to high levels of contamination under varying temperatures and relative humidity (RH), resulting in ambient stresses. The ambient stresses significantly contribute to the degradation of stator insulation, making PD diagnostics challenging. In this article, the effect of contamination under varying temperature and RH in electrical EM insulation is investigated through PD diagnostics. The variations in PD intensity is investigated under varying environmental conditions. PD measurements were carried out within an artificial industrial environment inside a climate-controlled chamber. Various PD features were extracted to study probability distribution functions to further investigate the PD severity at various levels of contamination, under varying temperatures and RH. Based on the experimental results, it was revealed that PD activity within the EM insulation was significantly affected by temperature and RH under varying contamination conditions. The proposed methodology is believed to be helpful in reliability assessments for a wide range of industrial applications.