Arcing Phenomena and the Application for Fault Location in SF6-Lnsulated Equipment

Development of a GIS fault location system

“…On the other hand, the SP relay will make the contact if the pressure wave of the gas section where it is installed or the pressure rise within a fixed time exceeds a certain level [4,5]. Therefore, by installing SP relays in the gas sections of the respective bays, simplified data handling in the system and simplified data processing content will become possible.…”

“…The pressure variation occurring due to the fault arc propagates inside the gas with the speed of sound [4]. At the main bus, since the piping distance between the gas sections is about 50 cm to 1 m, the operation time difference of the SP relays between adjacent gas sections is between 3 and 7 ms.…”

“…The operating characteristics are given in Ref. 4; the pressure variation phenomena due to the fault arc have been reported in Refs. 4 and 5.…”

“…In the case of fault arc currents exceeding 10 kA, shock gas pressure waves will occur when they are relatively large and the SP relay will operate as a result. On the other hand, when the fault arc current is below 10 kA, shock gas pressure waves will not occur and the SP relay will instead operate due to the pressure rise of the entire gas section where the arc has occurred [4,5].…”

“…3 and have investigated the effects. Table 1 shows As to the rise time of the pressure waves, the tests are carried out for the case of a steep wave corresponding to the shock gas pressure wave, and the case of a slow-wave-front wave corresponding to the pressure rise of the entire gas section, in such a way that the results would be as close as possible to the measured results of the pressure variations in the fault arc tests conducted in the past [4,5]; however, for the steep wave, due to the limitations of the test equipment, the tests are carried out with pressure waves of a little slower rise.…”