| Autor: |
Muhammad Farasat Abbas, He Yan-Liang, Han-Wei Li, Guan-Jun Zhang, Anbang Sun |
| Rok vydání: |
2019 |
| Předmět: |
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| Zdroj: |
2019 IEEE Conference on Electrical Insulation and Dielectric Phenomena (CEIDP). |
| Popis: |
SF 6 is a strong electronegative gas and used as insulating material in gas-insulated switchgear (GIS). For the efficient and reliable operation of GIS, it is necessary to investigate non-uniform field breakdown in SF 6 . Generation of free electrons is an essential prerequisite for initiation and propagation of positive discharges. A 3D particle-in-cell MonteCarlo collision (PIC-MCC) model is used to investigate the initiation of positive needle-to-plane streamer discharge in SF 6 with field ionization at pressures ranging from 1 to 5 bar. Free electrons are generated from impurity molecules with low density and low ionization energy in SF6 because of field ionization. The local electric field dependent electron generation rate is calculated using Zener’s model. Two stages of tree like streamer discharge are observed. In first phase, a spherical shape inception cloud is formed around the needle tip, which eventually destabilizes into multiple branches in the next stage. With the increase in pressure, the decrease in particle density, number of branches and total propagation length of streamer discharge is observed. The simulation results show that field ionization could be the possible source of ionization in SF6 in the presence of high electric field. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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