Study on Influencing Factors of SF6 Decomposition Products Detection Results

Because of its excellent insulation and arc extinguishing performance, Sulfur hexafluoride (SF ₆ ) is widely used in electrical equipment such as gas insulated switchgear (GIS), circuit breakers, transformers. The detection of the components and contents of the decomposition products of SF ₆ can provide an effective basis for the running state, abnormality or latent faults of SF ₆ gas insulated electrical equipment in time. In order to ensure the accuracy and reliability of the results, this paper analyzed many cases in which SF ₆ gas insulated electrical equipment were abnormal or broken-down in recent years, and made an in-depth study on multiple influence factors, such as sampling vessel material, sampling time, detection time, SF ₆ decomposition products auto hydrolysis or be adsorbed by adsorbent and equipment structure. The results show that sampling by stainless steel bottles with fluorine coating, comprehensive investigation of the SF ₆ gas decomposition products (such as SO ₂ F ₂ , SOF ₂ ) that could characterize the fault, going to the scene as soon as possible or carrying out the inspection work through online device, fully considering the different detailed structure of electrical equipment are of important significance to improve the supervision level of SF ₆ electrical equipment and achieve diagnosis and prediction when SF ₆ electrical equipment gets fault.