摘要
以SF6气体为绝缘介质的直流气体绝缘输电线路(gas insulated transmission lines,GIL)内部存在沿面缺陷,而局部放电信号蕴含了丰富的绝缘信息,因此针对直流电压下SF6气体沿面局部放电特性研究具有重要意义。为此以沿面模型作为试验模型,搭建直流高压试验平台,利用脉冲电流法对直流电场下SF6气体沿面放电过程中放电信号进行了统计,分析并提取沿面放电统计特征图谱的多个典型特征参数,研究局部放电起始特性与放电发展特性。研究表明:压强在0.1~0.6 MPa范围内,起始放电电压(partial discharge inception voltage,PDIV)具有极性效应,负极性PDIV更低,PDIV随着气压的增大而提高,PDIV对气压的敏感度随气压的升高而降低,放电稳定性随着气压的升高先降低后提高;当压强相同时,随着外施电压的提高,促进沿面放电发展,平均放电量和最大放电量不断增大,放电重复频率先升高后降低。根据放电特性的不同,将沿面放电过程分为4个阶段:初始电子主导放电阶段、电子崩主导放电阶段、流注发展阶段和临界击穿阶段;当外施场强一定时,提高压强会明显地抑制沿面放电发展,且抑制效果随着压强的提高而略有减弱。
There are surface defects in the DC gas insulated transmission lines(GIL)with SF6 gas as the insulating medium,and the partial discharge signal contains rich insulation information.Therefore,it is of great significance to study the partial discharge characteristics of SF6 gas along the direct current voltage.In this paper,the surface model is used as the experimental model to build a DC high voltage test platform.The pulse current method is used to calculate the discharge signal of the SF6 during the surface discharge under DC electric field.The typical characteristic parameters of the statistical data of the surface discharge are analyzed and extracted.The initial discharge characteristics and discharge development characteristics are studied and analyzed.Studies have shown that when the air pressure is in the range of 0.1 to 0.6 MPa,the partial discharge inception voltage(PDIV)has a polarity effect.The negative PDIV is lower,the PDIV increases with the increase of gas pressure,and the sensitivity of PDIV to air pressure increases with the pressure.The discharge stability decreases first and then increases with the increase of air pressure.When the pressure is the same,the creeping discharge is promoted with the increase of applied voltage,the average discharge amount and the maximum discharge amount increase,and the discharge repetition rate first increases and then decreases.According to the difference of discharge characteristics,the surface discharge process is divided into initial electron dominant discharge phase,electron collapse dominant discharge phase,flow injection development phase,and critical breakdown phase.When the external field strength is constant,increasing the pressure will significantly inhibit the development of the discharge,and the inhibition effect will be slightly weakened with the increase of the pressure.
作者
侯志强
孙善源
郭若琛
庞培川
李军浩
HOU Zhiqiang;SUN Shanyuan;GUO Ruochen;PANG Peichuan;LI Junhao(State Key Laboratory of Electrical Insulation and Power Equipment,Xi’an Jiaotong University,Xi’an 710049,China)
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2020年第5期1649-1657,共9页
High Voltage Engineering
基金
国家自然科学基金(51877169)。
