Analysis of Decomposition Products Due to Floating Potential Discharge in SF_6 Circuit Breaker

Abnormal content of SO2 gas was detected in a 126 kV SF6 circuit breaker,which inferred a latent fault in this circuit breaker.Theoretical analysis and disassembling inspection of the circuit breaker indicated that this latent fault was due to floating potential discharge in this circuit breaker.This paper analyses the forming process of floating potential and its influence on the operating characteristics of the circuit breaker.And the generation mechanisms of gaseous and solid decomposition products of SF6 gas under floating potential discharge are discussed.