直流电晕放电特性分析

Analysis of Direct Current Corona Discharge Characteristics

电晕放电产生的空间电荷在电场中的运动形成电晕电流。电晕电流产生的线路损耗会增加输电成本,对线路通道的电磁环境造成干扰。建立自洽的等离子体模型和简化的电晕放电模型,放电通过施加到内部电极的高压直流电源在同轴配置的两个电极内持续进行。从微观角度分析大气压下干空气中的正负电晕放电的物理过程,重点研究负极带电粒子的产生和输送,以及如何转化为放电的电流-电压特性。结果表明:电晕放电主要在电离区和传输区进行,正负电晕放电特征各不相同,两种模型下获得的电势和空间电荷密度计算结果具有很好的一致性。在负电晕放电中,电子是能量传递的主要载体,电荷分离不会使外加电势的分布发生形变。

Corona current is formed by the motion of space charge generated by corona discharge in the electric field.The line loss caused by corona current will increase the transmission cost and cause interference to the electromagnetic environment of the line channel.A self-consistent plasma model and a simplified corona discharge model was established.The discharge continued in two coaxial electrodes through a high-voltage DC power supply applied to the internal electrode.The physical process of positive and negative corona discharge in dry air at atmospheric pressure was analyzed from a microscopic point of view,focusing on the generation and transport of negative charged particles and how to convert them into current-voltage characteristics of discharge.The results show that corona discharge is mainly occurs in the ionization region and the transfer region,and the characteristics of positive and negative corona discharge are different.The calculated results of potential and space charge density obtained under the two models are in good agreement.In negative corona discharge,electrons are the main carrier of energy transfer,and charge separation will not deform the distribution of applied potential.