Research On The Influence Of VFTO On Disconnector Chamber In GIS

Compared with open type high-voltage distribution device，GIS has outstandingadvantage，but it also has disadvantage，which is the VFTO threats its internal and externaldevice，disconnector is very important in the GIS，so study on the influence of the VFTOon disconnector chamber in GIS is great significance.First of all，on the basis of the actual structure of disconnector chamber，disconnectorarc state circuit model is built，and the paper also calculates the capacitance to ground ofbasin type insulator in disconnector chamber，gives the models and parameters ofimportant components in GIS，and figures out the VFTO wave of the left basin typeinsulator，moving contact，static contact and the right basin type insulator in disconnectorchamber. In order to analyze transient electric field under the VFTO，the frequencies andamplitudes of the VFTO are extracted.Then，based on the actual structure of disconnector chamber，the finite element modelof GIS disconnector break and basin type insulator are established，combined withnonlinear relation of the VFTO frequency and insulation material dielectric constant，thepaper calculates electric field and electric potential distribution of disconnector break andelectric potential distribution of basin type insulator under every frequency component，inthe meantime calculates electric potential distribution of the disconnector break and basintype insulator，and calculates surface electric field intensity distribution of moving contact，static contact shield and basin type insulator，and calculates normal and tangential electricfield intensity distribution the upper and lower surface of basin type insulator underinteraction of various components and power frequency voltage，furthermore，Comparesboth situation.The calculation results show that they both have a high score in the local position，butthe score is higher under the VFTO，this means we must consider the influence of theVFTO when we analyse insulating property and design product. Finally，because the insulating medium has relaxation polarization that makes themedium interior fever which causes dielectric dissipation，because of the limited time，thispaper only briefly analyzes fever situation of basin type insulator，which provides areference for design of insulation materials in GIS.