表面喷砂对有机玻璃沿面闪络性能影响

绝缘子表面粗糙处理是提升其沿面闪络性能的重要途径,表面粗糙化处理方式不当,极易带来表面结构不均匀,难以获得稳定耐压性能的绝缘材料。为提升绝缘子表面粗糙处理的均匀性,本文利用表面喷砂技术对圆柱形有机玻璃(PMMA)绝缘子进行了粗糙化处理研究,以球形二氧化硅(SiO2)颗粒为工作介质,研究了不同喷砂粒径、氢氟酸后处理等因素对绝缘材料表面形貌和组分的影响,并利用短脉冲高压测试平台对喷砂处理前后有机玻璃绝缘子样品进行了真空沿面闪络性能测试。研究结果表明,喷砂处理在有机玻璃表面形成了较为均匀的凹坑,HF酸能够有效去除表面残留的SiO2颗粒,具有表面喷砂粗糙结构的绝缘子沿面闪络电压得到了稳定提升,相较于未处理的绝缘子闪络电压提升了约80%。

Influence of surface sand blasting treatment on vacuum surface flashover characteristics of PMMA insulator

Surface roughening treatment on insulators is an important way to improve their vacuum surface flashover characteristics. However, flashover voltages of the insulators with the same roughness show big deviation because of the poor uniformity of the surface rough structure and bad repeatability of the surface roughening method. To improve the uniformity of the surface roughening and the stability of the voltage-withstanding of the vacuum insulators, sand blasting roughening treatment on the surface of the cylindrical PMMA insulators was studied. First of all, the cylindrical insulators were sprayed on the rotating platform. With the collisions of the spherical micro SiO₂ particles carried by the high-speed airflow, rough structure was fabricated on the surface. After the corrosion of the HF acid, residual SiO₂ particles were removed, leaving homogeneous rough structure on the surface. The changes of the surface morphology were studied by Scanning Electron Microscope and the surface roughness of the treated insulators was tested on the surface roughness meter. Surface flashover characteristics of the sand-sprayed PMMA specimens were tested on the short-pulsed high-voltage platform. The test results indicated that homogeneously rough surface was prepared by the sand blasting treatment and the surface flashover voltages of the treated insulators were improved steadily. Compared with the untreated PMMA specimens, flashover voltages of the sand blasted insulators were improved approximately 80%.