中文摘要：

雷电冲击电压下变压器绝缘的局部放电特性对其过电压防护及故障诊断有重要意义,而目前相关研究较为缺乏。为此,选取油纸气隙、悬浮金属和针板油隙这3种典型油纸缺陷,通过试验分别研究它们在标准雷电冲击电压（波前时间为1.2×（1±30%）μs,半峰值时间为50×（1±20%）μs）下的局部放电特征,并结合仿真对现象进行解释。试验结果表明：1油纸气隙、悬浮金属、针板油隙这3种缺陷的局部放电电压时域波形差异显著：油纸气隙局部放电电压波形由雷电冲击电压波前时间附近产生的放电主脉冲和分布于半峰值时间后的大量小幅放电脉冲组成,悬浮金属和针板油隙的局部放电电压波形均为分布于半峰值时间内的大幅值密集簇状放电脉冲;2随着雷电冲击电压幅值的升高,3种缺陷的放电脉冲数均显著增加,油纸气隙缺陷平均放电电压幅值缓慢降低,悬浮金属和针板油隙缺陷平均放电电压幅值均有所增加。

英文摘要：

The characteristics of partial discharge in transformer insulation under lightning impulse voltage is significant to its over voltage protection and fault diagnosis. Consequently, selecting oil-paper gap, floating metal, and needle-plate model as typical defectsin oil-paper insulation, we studied the characteristics of discharge within the defects under lightning impulse （wavefront time 1.2×（1±30%）μs, harf peak time50×（1±20%）μs） through the methods of experiment and simulation. The results show that the time domain waveforms of partial discharge in the three typical defects show significant differences, namely, the waveform of oil-paper gap consists of a few main pulses appearing during the wave- front time of lightning impulse and many small pulses appear after the half-peak time of lightning impulse, while the waveforms of floating metal and needle-plate defects consist of large dense clusters of discharge pulses mainly distribut- ing before the half peak time; moreover, with the increasing of lightning impulse voltage, the numbers of discharge pulse in the three typical defects remarkably increase, and the average discharge capacity of oil-paper gap slowly decreases while that of floating metal and needle-plate increases.