GIS 绝缘子表面固定金属颗粒放电特性研究

摘要

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。%To study discharge characteristics of fixed metal particles on basin insulator surface of gas insulated switch-gear(GIS),a 220kV GIS partial discharge detection platform is constructed,on which the discharge model of fixed metal particles on GIS insulator surface is simulated. Ultraviolet imaging technology,ultrasonic testing technology and pulse current method are used to detect the whole discharge process. Based on data analysis,the following conclusions can be drawn:Ultraviolet imaging technology is highly sensitive,and the number of UV photons can reflect discharge intensity and location directly. The shape of fixed metal particles on insulator surface has a great impact on discharge intensity. In basin insulator defects,due to discharge intensification,the local defect area instantaneously expands with heat. The dramatic volume change will cause instantaneous change of medium density,therefore leads to ultra-sonic signal increase.