绝缘子气隙缺陷下的局部放电发展过程研究

Research on the development process of partialdischarge in GIS due to insulator gap defects

研究了气体绝缘组合电器(gas insulated switchgear, GIS)内部绝缘子气隙缺陷局部放电(partial discharge, PD)发展过程,分析了不同发展阶段的特高频(ultra high frequency, UHF)PD信号φ-u散点图和φ-n谱图变化规律,提出了9个特征参量。研究发现:正负半周放电次数、大小具有相同的变化规律,正负半周最大放电脉冲幅值、等值累积放电量和放电信号熵特征呈指数增长趋势,相邻放电脉冲平均时间间隔呈现近似指数衰减趋势。负半周相邻放电脉冲时间间隔总是大于正半周,并且两者差异性随着PD的发展逐渐缩小。相邻放电脉冲最大时间间隔随放电发展逐渐减小。最后,本文结合PD发展物理微观过程,分析了各特征量出现相关变化规律的物理机制。

The paper examines the development of partial discharge(PD)in gas-insulated switchgear(GIS)due to insulator gap defects.It analyzes the evolution of ultra-high frequency(UHF)PD signals throughφ-u scatter plots andφ-n spectrograms at different stages and introduces nine characteristic parameters.The study reveals consistent discharge occurrence patterns during negative and positive half-cycles.Findings show that the frequency and magnitude of discharges during positive and negative half-cycles follow a consistent pattern.Maximum discharge pulse amplitudes and cumulative discharge volumes display exponential growth,while the average intervals between adjacent PD pulses decrease exponentially.Notably,the time intervals between pulses during negative half-cycles consistently exceed those in positive half-cycles,diminishing this difference as PD progresses.The maximum time intervals between discharges also decrease over time.The study provides insights into the physical mechanisms driving these observed changes,correlating them with the microphysical processes of PD evolution.