检测GIS固体绝缘内部放电缺陷的特高频和X射线数字成像联合方法研究

Combined Ultra-high Frequency and X-ray Digital Imaging Method for Detecting Discharge Defects in GIS Solid Insulation

相比超声波局部放电检测法,特高频局部放电检测法对GIS固体绝缘内部放电缺陷检测灵敏度和定位精度较高,但由于无法确证此类缺陷部位和类型,据此制定的设备检修策略难以保证完善、准确。因此,本文研究了特高频局部放电和X射线数字成像联合检测GIS固体绝缘内部放电缺陷的方法,使用特高频局部放电检测法对固体绝缘缺陷进行检测和定位后,在设备检修期间应用X射线数字成像技术对缺陷进行可视化确证。该方法在某110 kV变电站110 kV GIS的带电检测中成功发现隔离开关绝缘拉杆内部电树枝缺陷,表明该方法有助于提升GIS固体绝缘内部局部放电的检测和定位效果,为检修提供可靠依据。

Compared with the ultrasonic partial discharge detection method, the ultra-high frequency partial discharge detection method detects and locates discharge defects in GIS solid insulation more effectively. However, because the position and type of the internal discharge defect cannot be definitely confirmed, the equipment maintenance strategy based on the result from this method is difficult to ensure perfection and accuracy. In this study, a combined ultra-high frequency and X-ray digital imaging method for detecting partial discharge defects in GIS solid insulation was proposed, in which the ultra-high frequency partial discharge detection method is first adopted to detect and locate the internal partial discharge defect, then the X-ray digital imaging method is adopted to visually confirm the defect in equipment maintenance. In a 110 kV GIS live detection in a 110 kV substation, an electrical tree defect within the insulated pull rod of a disconnector was detected by the proposed method, verifying that this method can improve the detection and location of the partial discharge defects in GIS solid insulation, so as to provide reliable defect information for maintenance.