Studies on mechanisms of arc propagation in vacuum involving multiple power circuits

Time and again geosynchronous communication satellites worldwide are plagued by unexpected power failures due to sustained arcing in power systems, the phenomenon which is under vigorous investigation. Though many studies have been conducted on arc phenomenon across polarized electrodes, very little attention is paid on the propagation of an initialized arc into adjacent power carrying conductors. Considering the complexity of theorizing the vacuum arc phenomenon accompanied with the ever increasing demand for high power satellites and greater reliability necessitates the devising of experiments to gather deeper insight into the arc phenomenon. The present paper discusses the experimental studies to understand the sustenance and propagation of an electric arc with respect to potential difference, current, electric field, vacuum level, and materials involved. The experiments establishes an operating threshold for current and vacuum level beyond which an initiated arc can propagate and create a short in the adjacent circuits of a power transfer assembly and thus likely to destabilize the system. The steps to mitigate the undesirable effects of arc propagation in a power transfer assembly are also discussed. The studies are conducted as part of development of high power transfer assembly for Geo-applications.