J Shanghai Jiaotong Univ Sci ›› 2024, Vol. 29 ›› Issue (2): 202-215.doi: 10.1007/s12204-022-2562-y

• Energy and Power Engineering • Previous Articles     Next Articles

Numerical Study on Comparison of Negative and Positive Surface Discharge in c-C4F8/CF3I/CO2 Gas Mixture


FAN Binhai1,2 (范彬海), ZHOU Xiaoli2* (周小丽),QIAN Yong3 (钱勇), ZANG Yiming3 (臧奕茗)   

  1. (1. Academy for Engineering & Technology, Fudan University, Shanghai 200433, China; 2. Department of Light Sources and Illuminating Engineering, School of Information Science and Technology, Fudan University, Shanghai 200433, China; 3. Department of Electronic Engineering, Shanghai Jiao Tong University, Shanghai 200240, China)
  2. (1.复旦大学 工程与应用技术研究院,上海 200433;2. 复旦大学 信息科学与工程学院 光源与照明工程系,上海 200433;3. 上海交通大学 电气工程系,上海 200240)
  • Accepted:2022-02-11 Online:2024-03-28 Published:2024-03-26

Abstract: The dynamics of negative surface discharges in c-C4F8/CF3I/CO2 gas mixture is investigated here with a 2D fluid model. The distributions of ion concentration, electric field strength and photon flux during the propagation of the streamer are obtained by solving the drift-diffusion equations of particles and Poisson’s equation, and the photon flux variation function during the propagation is also fitted. It is found that the streamer branches occur when the streamer transitions from the upper surface of the insulator to the side surface, and then when the streamer approaches the plane electrode, the photon flux will increase significantly. On this basis, the positive and negative surface discharge models are compared in terms of streamer characteristics, particle characteristics and streamer branches. It is found that the streamer has a higher electron concentration and electric field in the positive model. The streamer develops “floating” in the positive surface discharge, while it is close to the surface of the insulator in the negative model. In addition, the negative streamer branch has a wider width and develops further.

Key words: streamer branch, surface discharge, c-C4F8/CF3I/CO2 gas mixture, positive and negative models

摘要: 基于二维流体模型,研究了c-C4F8/CF3I/CO2混合气体中的负沿面放电过程。通过求解粒子的漂移扩散方程和泊松方程,计算出流注传播过程中离子浓度、电场强度和光通量的分布,并拟合出了传播过程中光通量的变化函数。结果发现,当流注从绝缘子上表面过渡到侧面时,流注开始分散,出现了流注分支;当流注接近平板电极时,光通量会显著增加。在此基础上,对比了正负沿面放电模型在放电过程中的流注特征、粒子特征和流注分支等方面。结果表明,正沿面放电模型中的流注具有更高的电子浓度和电场。在正沿面放电模型中,流注会呈“悬浮”状态,而在负沿面放电中,则是紧贴绝缘体表面发展。此外,负极性流注分支更宽,发展得更远。

关键词: 流注分支,沿面放电,c-C4F8/CF3I/CO2混合气体,正负电极模型

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