WU Xixiu, CHENG Shimin, ZHOU Fan, et al. Influence of Temperature Rise due to Rated-current Flowing Through Busbar on the Internal Insulation Characteristics of GIS: A Simulation Study[J]. High voltageapparatus, 2020, 56(2): 7-14.
WU Xixiu, CHENG Shimin, ZHOU Fan, et al. Influence of Temperature Rise due to Rated-current Flowing Through Busbar on the Internal Insulation Characteristics of GIS: A Simulation Study[J]. High voltageapparatus, 2020, 56(2): 7-14. DOI: 10.13296/j.1001-1609.hva.2020.02.002.
Influence of Temperature Rise due to Rated-current Flowing Through Busbar on the Internal Insulation Characteristics of GIS: A Simulation Study
Temperature rise phenomena occurs when rated current flows through the busbar of GIS
which results in SF6 gas flowing and ultimately makes it distribute unevenly.The uneven SF6 distribution greatly influences its breakdown characteristics
and may easily cause partial discharge in local uneven distribution area and then lead to insulation faults.In this paper
an electromagnetic-temperature-flow multi-physical field coupling model considering eddy effect
skin effect
a
nd temperature rise effect of conductivity is established to analyze the flowing characteristics of SF6 in the 1 100 kV GIS.The results show that the higher the temperature rise
the thinner the SF
6
gas distribution and the lower the insulation level of GIS.To quantitatively evaluate the internal insulation condition of GIS
the relationship between critical breakdown strength and SF6 gas distribution is analyzed and the concept of insulation margin is defined.Subsequently
a mathematical model is set up to calculate the internal insulation margin of GIS.The results show that the temperature rise due to current flowing through the busbar makes the internal insulation level of GIS decrease dramatically from 14.51 kV/mm to 9.92 kV/mm
which implies that under this condition the GIS will be easily broken-down if it surfers high voltage impulse such as lightning.It is concluded that that the influence of this temperature rise on the internal insulation level of GIS cannot be ignored in insulation design of GIS.