Corona discharge, an inevitable phenomenon, may lead to insulation degradation, threatening the safe and reliable operation of gas-insulated power equipment. The pulse stage is a complex but usual discharge process in corona discharge. In this paper, we investigate the pulse characteristics of negative corona discharge in a needle-to-plane electrode configuration in SF₆/N₂ gas mixtures under DC voltages. With an increase in mean current, a stage transition phenomenon from the Townsend stage through the pulse stage to the breakdown stage is observed. The variation in pulse amplitude and pulse time characteristics at the pulse stage is analyzed. In addition, the effects of gas pressure, gap spacing, and N₂ content on onset voltage and pulse characteristic parameters, including pulse time parameters and the pulse repetition rate, at the pulse stage are presented. The results show that the current pulses mainly exhibit an irregular distribution of small amplitude. The pulse time parameters are not affected by gas pressure, gap spacing, or N₂ content at pressures higher than 0.1 MPa. The pulse repetition rate decreases with an increase in gas pressure and N₂ content but is only weakly affected by gap spacing, ranging from 1 kHz to dozens of kHz.

中文翻译：

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直流电压下SF6 / N2混合气负电晕放电脉冲特性的实验研究

电晕放电是不可避免的现象，可能会导致绝缘性能下降，从而威胁到气体绝缘电力设备的安全可靠运行。在电晕放电中，脉冲级是一个复杂但通常的放电过程。在本文中，我们研究了在DC电压下SF ₆ / N ₂混合气体中针形电极结构中负电晕放电的脉冲特性。随着平均电流的增加，观察到从汤森阶段到脉冲阶段到击穿阶段的阶段过渡现象。分析了脉冲阶段的脉冲幅度和脉冲时间特性的变化。此外，气体压力，间隙间距和N _2的影响介绍了脉冲阶段的起始电压和脉冲特性参数的内容，包括脉冲时间参数和脉冲重复率。结果表明，电流脉冲主要表现出小幅度的不规则分布。在高于0.1 MPa的压力下，脉冲时间参数不受气压，间隙间距或N ₂含量的影响。脉冲重复频率随气压和N ₂含量的增加而降低，但仅受间隙间隔（范围为1 kHz至数十kHz）的微弱影响。