Ion mobility spectrometry for on-site sensing of SF/sub 6/ decomposition

Although gas-insulated system (GIS) and substations belong to the most reliable components of electric power networks, failures still occur in their long-term operation. In order to estimate the probability of malfunctions in advance, a system for monitoring the quality of the insulating gas SF/sub 6/ was established, which is based on the use of ion mobility spectrometry (IMS). In a set of experiments, partial discharge (PD) was generated inside a test GIS. The SF/sub 6/ was periodically analyzed using IMS. The results of this analysis is presented and the influence of impurities remaining inside the compartment is discussed. The analysis of gas contained in a circuit breaker in a hydroelectric power plant before and after operation is described as well as the structure of a system for automatic on-site sensing of SF/sub 6/ decomposition.