空气正极性电晕放电微观仿真及模型系数对脉冲电流特性的影响

Micro-simulation of Air Positive Corona and the Influence of Model Coefficient on Pulse Current Characteristics

为了研究空气电晕放电的发展过程和微观机理,建立了二维轴对称针-板放电微观仿真的流体动力学模型,研究了空气正极性电晕放电的微观过程、间隙电场和微观粒子的时空分布,以及放电脉冲的波形特性。研究表明:空气正极性电晕放电的脉冲电流主要分为电流急速上升、电流急速下降以及放电休克3个阶段;脉冲电流的上升时间、相邻脉冲的时间间隔,以及脉冲电流的平均峰值及峰值变化趋势可以作为放电电流的特性参数。进一步研究表明,脉冲电流的平均峰值大小与仿真模型中的电离系数、二次电子发射系数、正离子迁移率正相关,与附着系数负相关;脉冲电流的上升时间和相邻脉冲的时间间隔随正离子迁移率增大而减小,但基本不受其他3个放电系数的影响。

In order to study the process and micro mechanism of air corona discharge,a two-dimensional axisymmetric hydrodynamic model of needle-plate discharge is established in this paper.The microcosmic process of air positive corona,the space-time distribution of its electric field and charged particles,and the waveform characteristics of discharge pulse are studied.The results show that the pulse current of air positive corona includes three stages,namely,rapid rise,rapid decline,and discharge shock;the rise time of pulse current,the time interval between adjacent pulses,the average peak value and the change trend of peak value can be as the characteristic parameters of discharge current.The further analysis shows that the average amplitude has a positive relation with the ionization coefficient,positive ion mobility and secondary ion mobility,while has a negative relation with adhesion coefficient.The rise time of pulse current and the time interval between adjacent pulses decrease with the increase of positive ion mobility,but they are not affected by the other three model coefficients.