Finite element modeling of circuit breaker switching emissions´ propagation in GIS

Finite element modal analysis is used to predict the frequency spectrum of switching emissions from gas insulated substation switchgear. Field results indicate that the arc can be modeled as an impulsive current source. Fields of resonant modes matching the fields emitted by the arc facilitate the excitement of these modes and shape the spectrum of the emissions. The data provided by the model can be used to identify signal sources and complement a time domain based on-line circuit breaker contact timing system.