SF_(6)气体中交流电晕放电电流及带电粒子的时空分布

Discharge Current and Charged Speciesê Temporal-spatial Distribution of AC Corona Discharge in SF_(6)

SF_(6)气体中电晕放电微观物理化学过程的基础研究对于保障电网安全可靠运行非常重要。为此在负极性电晕放电脉冲形成机制研究工作的基础上,应用同样的针-板电极电晕放电的二维轴对称模型来研究交流50Hz下SF_(6)气体中电晕放电的微观物理化学过程,并采用在连续性方程中增加常数项和设置初始质量浓度这2种方法来模拟光电离,计算了交流电晕放电1个放电周期的电流及不同时刻带电粒子的时空分布。结果表明:在连续性方程中增加常数项模拟光电离能够获得负半周幅值附近的连续性电流脉冲,与试验结果更为接近;正负半周带电粒子的运动方向正好相反;电晕放电区域的高度为8mm,且有效放电半径≤0.20mm。放电区域的获取能够为进一步研究SF_(6)气体在交流50 Hz电晕放电中的分解产物的演化规律提供理论支撑。

Fundamental research on the micro physic-chemical processes of corona discharge in SF_(6) gas is particularly important to ensure the safe and reliable performance of power grids. In this paper, the same 2 D axisymmetric model was applied to study the micro physico-chemical processes of 50 Hz AC point-plane corona discharge in SF_(6) gas based on the research of the formation mechanism of pulses in negative corona discharge. The photoionization was simulated by adding a constant term in the continuity equations and setting the initial mass concentrations. The discharge current and the temporal and spatial distributions of the charged species in different time instants of a discharge cycle were obtained. The results show that the continuous current pulses near the magnitude of negative half-cycle can be obtained by adding a constant term in the continuity equations to simulate photoionization, which is closer to the experimental results. In addition, the movement of the charged species in the positive and negative half cycles is opposite. The height of the discharge region is 8 mm, and the effective radius of the discharge region does not exceed 0.2 mm. The acquisition of the discharge area can provide theoretical support for the further research on the evolution regulation of decomposition products of 50 Hz AC point-plane corona discharge in SF_(6) gas.