SF6中氧化铝环氧复合材料的纳秒脉冲闪络特性

氧化铝掺杂环氧树脂复合材料在电力绝缘设备中应用广泛，然而人们对其在纳秒脉冲下的绝缘性能研究较少，这限制了它在指导脉冲功率装置中的应用。为探究其在纳秒脉冲下的沿面绝缘性能，对氧化铝掺杂环氧树脂复合材料在前沿数十ns快脉冲电压下的闪络特性进行了研究，结果显示，其闪络电场较纯环氧有较大提高，闪络电压符合韦伯分布。实验表明，闪络电压随电压上升率的增加而显著增加，从5.8 kV/ns时的108 kV上升到20.5 kV/ns时的226 kV，增幅超过1倍。闪络时延随电压上升率的上升呈现“先快速下降、后趋于平缓”的趋势。在试样闪络通道表面观测到明显的碳化现象，说明实验中的闪络放电对复合材料有破坏性影响。

Flashover characteristics of epoxy/Al2O3 composite under nanosecond rising pulses in SF6 gas

Epoxy/Al₂O₃ composite is widely used as insulating material in power equipment. However, its performance in SF₆ gas under fast-rising pulse is little studied, which limits its application in guiding insulation design of pulse power devices. To investigate the insulation characteristics of epoxy/Al₂O₃ composite under nanosecond pulses, the flashover characteristics of this material are studied under pulse voltage with rise time of about 52 ns. The results show that its electric field of flashover is much higher than pure epoxy’s, and the flashover voltage is in accordance with Weibull distribution. The experiment shows that the flashover voltage increases significantly with the increase of the pulse steepness, from 108 kV at 5.8 kV/ns to 226 kV at 20.5 kV/ns. As pulse steepness increases, the flashover delay time decreases rapidly first, then tends to be flat. The surface morphology of the flashover area of the samples shows that the flashover channel is obviously carbonized and flashover discharge has a destructive effect on the composite material.