The electromagnetic effect study of GIS enclosure under high-frequency electromagnetic pulse

摘要

In gas insulated switchgear (GIS) substation, due to the operation of disconnect switch and circuit breaker, as well as short-circuit fault, SF6 will break down very rapidly. The superposition of refraction and reflection of high-frequency travelling waves will cause the very fast transient electromagnetic pulse (EMP). High-frequency EMP propagating along GIS core wire will couple to GIS enclosure which forms transient enclosure voltage (TEV). Through the study of new GIS enclosure coupling model which can be verified by site test and frequency effect on the enclosure coupling under high-frequency EMP, results indicate the generation of TEV is closely related to GIS structures and the electromagnetic wave propagation characteristics on its core wire and enclosure. Electromagnetic coupling model must consider the entire propagating and coupling process of EMP in GIS. Paper also shows that TEV is mainly formed by high frequency >0.1 MHz EMP coupling and the difference on coupling extent when frequency is >1 MHz is small.