GIS绝缘子表面固定金属颗粒放电特性研究

为研究气体绝缘开关设备中绝缘子表面固定金属颗粒的放电特性,在实验室建立了一套220kV电压等级的GIS局部放电检测平台,模拟GIS绝缘子表面固定金属颗粒放电模型,应用紫外成像技术、超声波检测技术和脉冲电流法对整个放电过程进行了检测。试验结果表明:光学检测法灵敏度很高,通过紫外光子数可以直观的反映放电的剧烈程度和放电位置;绝缘子表面固定金属颗粒的形状对放电剧烈程度有较大影响;在绝缘子缺陷处,随着放电的加剧,局部区域瞬间受热而膨胀,体积的剧烈变化引起了介质密度的瞬间变化,从而导致超声波信号不断增强。

Study of discharge characteristics of fixed metal particles on the GIS insulator surface

For studying the discharge characteristics of fixed metal particles on the basin insulator surface of GIS, a 220kV GIS partial discharge detection platform is taken to simulate discharge model of fixed metal particles on GIS insulator surface, and uses the ultraviolet imaging technology, ultrasonic testing technology and pulse current method are mainly used to detect the whole discharge process. Based on data analysis, the following conclusions can be concluded: 1) Ultraviolet imaging technology is highly sensitive, and the number of UV photons can directly reflect the discharge intensity. 2) The shape of fixed metal particles on the insulator surface have a great impact on discharge intensity. 3) In the basin insulator defects, collisions between charged particle become more intense with discharge intensifing. The collisions result in the increase of sound pressure in macro level, and lead to ultrasonic signal increasing.