直流电压下SF6/N2混合气体沿面局部放电特性  

Partial Discharge Characteristics of the Surface Discharge in SF6/N2 of the Mixed Gas Under DC Voltage

作　　者：侯志强 郭若琛 李军浩[1] Hou Zhiqiang;Guo Ruochen;Li Junhao(State Key Laboratory of Electrical Insulation and Power Equipment Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]电力设备电气绝缘国家重点实验室(西安交通大学),西安710049

出　　处：《电工技术学报》2020年第14期3087-3096,共10页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金资助项目(51877169)。

摘　　要：基于SF6的温室效应,以SF6/N2混合气体为绝缘介质在直流气体绝缘线路(GIL)中的应用受到广泛关注,而沿面缺陷是GIL常见缺陷之一,因此针对直流电压下SF6/N2混合气体沿面局部放电特性研究具有重要意义。该文利用脉冲电流法对放电信号进行提取,研究混合气体沿面局部起始放电特性和放电发展阶段的统计特征。研究表明:压强在0.1~0.8MPa范围内,起始放电电压(PDIV)随压强的增大而增大,最大放电量随压强的提高而下降,混合气体的协同效应随压强的增大更加明显;PDIV随SF6气体含量的增大而增大,PDIV的增速对SF6气体含量的敏感度下降,混合气体的协同效应随SF6气体含量的提高而降低。外施电场在PDIV^40kV范围内时,平均放电量在低压强区随外施电场的提高而增大;在高压强区随外施电场的提高基本保持不变,高压强区50%SF6混合气体的放电重复率高于低压强区,且随着放电发展有明显的抑制作用。沿面放电具有极性效应,负极性PDIV小于正极性PDIV。Due to the greenhouse effect of SF6,more and more scholars are paying attention to the application of SF6/N2 mixed gas as the insulating medium in DC GIL.The surface defect is one of the common defects of GIL,so it is of great significance to study the partial discharge characteristics of SF6/N2 mixed gas under DC voltage.In this paper,the discharge signal is statistically counted by the pulse current method,and the initial partial discharge characteristics and the statistical characteristics of the discharge development stage of the mixed gas are studied.The results show that,when the pressure is in the range of 0.1~0.8MPa,as the pressure increases,the partial discharge inception voltage(PDIV)and the synergistic effect of the mixed gas increase,while the maximum discharge decreases.As SF6 content decreases,the PDIV increases,the sensitivity of PDIV growth rate to SF6 gas content decreases,and the synergistic effect of the mixed gas decreases.When the applied electric field is in the range of PDIV to 40kV,the average discharge amount increases in the low-pressure region with the increase of the applied electric field,and the increase in the high-voltage region with the applied electric field remains unchanged.The discharge repetition rate of the 50%SF6 mixed gas in the high-pressure region is higher than that in the low-voltage region,and the formation of discharge is suppressed as the discharge develops.The surface discharge has a polar effect,and the negative PDIV is smaller than the positive PDIV.

关 键 词：直流电压 气体绝缘线路 SF6 N2 混合气体 局部放电 

分 类 号：TM855[电气工程—高电压与绝缘技术]