摘要
根据流注理论建立反映SF_6气体放电过程中微观粒子动力学特性的流体动力学模型,将有限单元法（finite element method,FEM）与通量校正传输法（flux corrected transport,FCT）相结合,通过循环迭代求解气体的放电过程,得到其击穿电压及空间电子数密度分布。为了证明上述方法的正确性,以均匀电场中气体间隙5mm为例进行数值计算,并通过搭建气体放电光谱实验平台,测量其击穿电压以及导电通道内的等离子体谱线信息,采用Stark展宽法及光强比值法对谱线进行分析,得到电子数密度等参量。在此基础上,分析气体压强对击穿电压及等离子体导电通道内电子温度、电子数密度的影响,建立宏观参量与微观参量的对应关系。研究结果表明：当气压为0.1~0.4 MPa时,SF_6的击穿电压与压强基本呈线性关系,计算结果与实验值随气压的变化趋势一致,但存在一定误差,最大误差为15.51%。电子温度随气压的升高而逐渐下降,0.4 MPa时降低到3.68×10~4K。等离子体导电通道形成时,空间电子数密度分布均匀,计算得到的平均值与实测数据均随压强的升高而增大,其最大误差为17.02%。所得的实验数据能够在一定程度上验证计算方法的正确性。
A hydrodynamic model based on the streamer theory was presented, which was to depict dynamic properties of micro particles in SF_6 discharge process. Combining the finite element method（FEM） and the flux corrected transport（FCT）, breakdown voltages and distribution of electron number density can be obtained by loop iterative solution of gas discharge processes. To prove it, a 5mm gas gap in an uniform electric field was used for computations as an example,an experimental platform of spectrum for gas discharge was set up to measure breakdown voltages and to get spectral information of plasma in conducting channels. Parameters like electron number density were got by applying methods such as stark broadening and light intensity ratio. On this basis, effects of gas pressure on breakdown voltages, electron temperature and electron number density in conducting channels were analyzed. Relationships between macroscopic parameters and microcosmic parameters were established. The results show that breakdown voltages of SF_6 have a linear relationship with pressure from 0.1 MPa to 0.4 MPa. Calculated results are consisted with experimental values in tendency changing with pressure, but small errors are also existed. The maximum error is 15.51%. The electron temperature is decreased gradually with pressure increasing, reducing to 3.68×10~4 K in 0.4 MPa. The distribution of electron number density is uniform when a conductive channel of plasmas is formed. Both computed average values and measured data increase with pressure, the maximum error is 17.02%. Experimental data can testify the computation method of breakdown voltages to some extent.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2016年第1期301-309,共9页
Proceedings of the CSEE
基金
国家自然科学基金项目(51277123)~~
关键词
流注理论
气体放电
击穿电压
SF_6
有限元法
通量校正传输法
streamer theory
gas discharge
breakdown voltage
SF_6
finite element method（FEM）
flux corrected transport（FCT）
