CF4及其N2混合物微观放电参数计算与绝缘特性仿真研究

Calculation of Discharge Micro-parameters and Simulation of Insulation Characteristics for CF4 and its N2 Mixture

为研究SF6替代气体CF4及其N2混合物微观放电参数,通过两项近似Boltzmann方程对室温环境下CF4及CF4/N2混合物在混合比为20%~80%区间内的有效电离系数(α-η)/N进行了求解分析。利用COMSOL Multiphysics多物理场仿真软件首次对CF4及CF4/N2混合物在均匀场下,不同混合比,不同压力条件下放电通道进行了一维模拟。仿真结果表明,CF4/N2混合物放电过程存在明显协同效应;CF4放电延时随气压增大而增大,仿真结果与数值计算结果吻合。

Aiming to study the discharge micro-parameter of CF4 and its N2 mixture,two-term approximation ofBoltzmann equation was used.And the reduced effective ionization coefficient(α-η)/N of CF4 and its N2 mixture inthe range of 20%~80%of the mixture ratio was calculated and analyzed.COMSOL Multiphysics simulation softwarewas used to imitate one-dimensional discharge channel of CF4 and CF4/N2 in different mixing ration and pressure,un-der uniform electric field at ambient temperature for the first time.The result shows that the breakdown voltage ofCF4/N2 mixture shows remarkable synergistic effect with CF4 mixing ratio increasing.And discharge delay time ofpure CF4 increases with pressure increasing.The simulation result is accordant with the numerical result.