正极性振荡型雷电冲击电压下的油纸绝缘沿面闪络特性

为了获得标准雷电和不同频率的振荡型雷电冲击电压下油纸绝缘沿面闪络特性的异同,在平行电场结构的油纸绝缘沿面试品上施加了标准雷电、100、200、300、400 kHz振荡雷电共5种冲击电压,对比分析了不同冲击电压作用下闪络特性。结果表明振荡型雷电冲击电压的10%及50%闪络电压均高于标准雷电冲击电压,伏秒特性曲线整体位于标准波之上。随着振荡频率的增大,10%及50%闪络电压逐渐增大,且伏秒特性逐渐上移,振荡型比标准雷电冲击电压的最大闪络时延长。采用Weibull概率分布研究了不同类型电压下的闪络概率,结果表明振荡型的概率曲线较标准波陡,且随着振荡频率的增大,概率分布曲线的斜率逐渐降低,即随着施加电压幅值的升高,振荡频率越低,其闪络概率增加越多。

Surface Flashover Characteristics of Oil-paper Insulation Under Positive Oscillating Lightning Impulse Voltage

In order to compare the different characteristics of flashover under different types of lightning waveform,four types of oscillating lightning impulse voltage(OLI)waveforms with oscillating frequency of 100,200,300 and 400 kHz were applied on oil-paper samples with parallel electric field.The standard lightning impulse(SLI)voltage was also adopted as the reference waveform.Characteristics of flashover under different types of lightning waveform were compared.The experimental results show that the 10%and 50%flashover voltages under OLI are higher than those under SLI.The voltage-time distributions under OLI are also higher.With the increase of oscillating frequency,the 10%and 50%flashover voltages increase and the voltage-time distribution gradually rises.The OLI has the longer time lag than SLI.The Weibull probability coordinate paper was applied to study the surface flashover probability.The experiment results show that the slope of OLI is larger than that of SLI,besides,with the increase of oscillating frequency,the slope of OLI gradually decreases.