摘要
GIS中隔离开关例行操作产生的特快速暂态过电压（VFTO）对GIS等电力设备绝缘造成很大威胁。目前,由于VFTO的非标准化,导致VFTO下GIS绝缘特性研究结果分散性大、可比性差。为此借助研制的陡前沿冲击试验装置,研究了便于标准化的双指数冲击电压下SF6稍不均匀电场棒–板间隙的放电特性。研究表明,稍不均匀电场下,不同波形参数冲击电压下间隙50%放电电压随气压升高基本呈线性增加,并且出现了极性效应反转现象,且极性反转临界气压值与波形参数有关。间隙50%放电电压随冲击电压波前时间增加无显著变化,略呈下凹＂U＂型;随波尾时间增加略有微弱下降趋势。结合VFTO波形基本特征和现场试验大容量负载的特殊情况,建议选取波前时间0.2-0.8μs、波尾时间1.2-15μs的双指数冲击电压作为VFTO模拟波形,进一步研究现场试验用VFTO标准波形。
Very fast transient overvoltages（VFTOs） generated during the routine operations of disconnector switch in gas-insulated metal-enclosed switchgear（GIS） greatly threaten the insulation of power equipment such as GIS. So far, the research results of the insulation characteristics of GIS under VFTO are dispersive and poorly comparable due to the non-standardized waveform parameters of VFTO. Using the steep fronted impulse generator, we studied the influences of impulse waveform parameters on the breakdown voltage in SF_6 quasi-uniform electric field. The results show that, with the rise of gas pressure, the 50% breakdown voltages increase with an approximate linear trend under impulses with different waveform parameters. The gas gap discharge has the reversal phenomenon of polarity effect, and the critical pressure of polarity reversion is connected with the impulses＇ waveform parameters. Meanwhile, the 50% breakdown voltages do not change significantly with the increase of impulse wave fronts and the 50% breakdown voltage-wave front time curves tend to be U-shaped. The 50% breakdown voltages decrease slightly with the increase of impulse wave tails. Considering the fundamental characteristics of VFTO waveforms and the special needs for the high capacity load in field test, the double-exponential impulses with wave front time of 0.2-0.8 μs and wave tail time of 1.2-15 μs are chosen as the simulated waveforms for VFTO to further study the field VFTO testing standard waveforms.
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2016年第3期936-941,共6页
High Voltage Engineering
作者简介
文韬1990-，男，博士生主要从事GIS绝缘特性研究E—mail：hv．wentao@stu．xjtu．edu．cn
张乔根（通信作者）1965-，男，博士，教授，博导主要从事气体绝缘与放电等离子技术、大功率脉冲技术及应用的研究E-mail：hvzhang@mail．xjtu．edu．cn
