Muhimman tasarin VFTO (Very Fast Transient Overvoltage) na GIS a tashar karkashin jirgin sama da EHV

 Maƙasun VFTO (Very Fast Transient Overvoltage) na karkashin cikin GIS na HV da EHV

Karamin karkashin gaba, tare da lokacin da yake fitarwa na nan ya kai tsawon 2 zuwa 20 nanosekondi: Idan an yi kawo kira-kira a cikin faduwar ziyartar disconnector, an yi kawo kira-kira waɗanda suka faru a fili. Saboda haka, karamin karkashin fitarwa ta kasance a kan abubuwan karamin karkashin mai karfi.

A halin lissafi, amfaniyar VFTO (Very Fast Transient Overvoltage) yana iya haɗa zuwa 3.0 per-unit. Wannan yanayin muhimmanci ta shafi ne idan alamar karamin karkashin cikin jerin darajar da ke nuna a bangaren banga-bangan suke magana da kuma suke haɗa zuwa manyan alamar. A lura ƙarin bayanai masu amfani a cikin yanayin, kamar karamin karkashin da aka fi sani, kungiyoyi, da kuma ƙananan, amfaniyar VFTO wanda aka samu a cikin bayanai ko kuma a cikin yanayin aiki ba ta iya haɗa zuwa 2.0 per-unit a duk wasu abubuwa. A cikin yanayin muhimmanci, amfaniyar karamin karkashin da ya fi haɗa ya zama 2.5 zuwa 2.8 per-unit.

VFTO na da karamin karkashin da suka fi ƙarin a ƙungiyar 30 kHz zuwa 100 MHz. Wannan shi ne saboda Gas-Insulated Switchgear (GIS) ta yi amfani da gasen sulfur hexafluoride (SF6) a cikin ƙungiyar, kuma harufar ingantaccen wannan gasen ya fi ƙarin da zuba.VFTO na da damar da kawo kira-kira da kuma kawo kira-kira a cikin GIS disconnector, kuma kafin da ƙungiyoyin disconnector a cikin abubuwan GIS.Tambayar ta nuna misal na karamin karkashin VFTO a cikin GIS na 750 kV.