环保气体下灰尘对环氧树脂闪络特性的影响

Effect of Dust in Environment-friendly Gas on Flashover Characteristics of Epoxy Resin

气体绝缘设备中环氧树脂绝缘子表面染污是引发其沿面闪络的重要原因,明确各类型灰尘对环氧树脂绝缘性能的影响具有重要的意义。采用3种材质粉末模拟气体封闭绝缘设备中可能出现的灰尘类型,并对各组附灰试样进行表面电荷特性测量分析,并在混合C4F7N-CO2气体环境中进行了工频交流沿面闪络测试。测试结果显示,金属类附灰电荷积聚量最多,绝缘类与半导体类附灰积聚电荷量相近;金属类附灰试样电荷消散速度最快,附半导体类其次,而绝缘类附灰试样消散最慢。金属类附灰试样沿面闪络电压随附灰粒径d减小而逐渐提高,半导体类、绝缘类附灰试样沿面闪络电压随d减小而逐渐降低;与经表面充电操作后的试样相比,未充电的试样(原试样)闪络电压较低。阐述了环氧树脂绝缘表面附着不同材质、不同粒径灰尘对于其表面电荷特性及沿面闪络特性的影响及二者间关联关系。

It is important to clarify the influence of various types of dust on the insulation performance of epoxy resin. In this paper, three kinds of material powders are used to simulate the dust types that may exist in gas-enclosed insulation equipment. Surface charge characteristics of each group of dust-attached samples are measured, and AC flashover test is carried out in a mixed C4F7N-CO2 gas environment. The results show that the charge accumulation of metal dust-attached samples is the largest, and that of insulating and semiconductor dust-attached samples is similar;the charge dissipation rate of metal dust-attached samples is the fastest, and that of semiconductor dust-attached samples is the second, while that of insulating dust-attached samples is the slowest. The flashover voltage along the surface of metal dust-attached samples increases with the decrease of diameter of particle grain(d), while that along the surface of semi-conductor and insulator ash-attached specimens decreases. Compared with the samples after surface charging operation, the flashover voltage of non-charged samples(original samples) is lower. The effects of different materials and d values of dust attached to the surface of epoxy resin insulation on its surface charge characteristics and flashover characteristics along the surface and the relationship between them are described.