Electrochemical Response Characteristics During the Oxidative Degradation of Gear Oil in Wind Turbine Generators

Electrochemical impedance spectroscopy (EIS), a rapid and non-destructive detection technique, offers a novel technical pathway for monitoring the degradation and assessing the quality of gear oil. This research delves into the electrochemical response characteristics and the underlying evolution mechanism of high-viscosity gear oil specifically formulated for wind turbines during its oxidative degradation process. Utilizing Mobil SHC™ Gear Oil 320 WT as the research subject, oil samples with varying degrees of degradation were prepared through accelerated oxidation experiments. Broadband frequency-sweep EIS testing was employed to acquire impedance spectra. The EIS data were subsequently analyzed using the equivalent circuit (ECM) method to extract electrochemical fingerprint parameters, enabling a systematic analysis of the variation patterns in the electrochemical response of gear oil with respect to oxidation temperature and time. Concurrently, the impact of test temperature on measurement results was evaluated. The findings reveal that EIS can dissect the intricate oxidative degradation process of gear oil into quantifiable interfacial electrochemical responses, with the characteristic parameters derived from ECM demonstrating consistent trends. Through a comprehensive analysis of the evolution patterns of electrochemical fingerprints, the oxidative degradation state of gear oil can be effectively evaluated. This research provides empirical evidence supporting the application of EIS technology in monitoring oxidative degradation and assessing the quality of gear oil for wind turbines.