Discharge Current and Charged Species' Temporal-spatial Distribution of AC Corona Discharge in SF6

Fundamental research on the micro physic-chemical processes of corona discharge in SF6 gas is particularly important to ensure the safe and reliable performance of power grids. In this paper, the same 2D axisymmetric model was applied to study the micro physico-chemical processes of 50 Hz AC point-plane corona discharge in SF6 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 SF6 gas. © 2021, High Voltage Engineering Editorial Department of CEPRI. All right reserved.