嵌件表面微米级铝杂质对GIS盆式绝缘子绝缘性能的影响OA

In the ultra-high voltage transmission,the reliable insulating performance of insulators is crucial for the safe operation of fully enclosed gas insulated switchgear(GIS).However,micron-sized aluminum impurities adhering to the surface of the embedded components of basin insulators are incorporated into the insulator during the pouring and assembly processes.This leads to electric field distortion around them,causing micro-discharges and posing a threat to the performance of the insulating material.Using COM-SOL,this study constructed a working model of a 220 kV epoxy resin pot insulator that incorporates the comprehensive effects of electromagnetic,thermal,and mechanical fields.We utilized actual measurements of aluminum particles as impurities in the model,and included air gaps around aluminum impurities for bubbles that are 100 μm or smaller,as permissible for insulator release.We al-so analyzed the electric field characteristics of deformed bubbles around aluminum impurities with different curvatures under differ-ent loads.The results indicate that near the central conductor,the maximum electric field intensity around the air gaps of aluminum blocks with small curvature and aluminum wires with large curvature increased by 258%and 343%respectively,compared to air bubbles of the same size order.Under the combined effect of eddy currents and heat transfer from the central conductor,the alumi-num impurities have displaced by a micron-level distance.It brings the discharge hazard area caused by the aluminum impurities closer to the central conductor to less than 1 mm.The results provide a reference for the analysis and detection of bubble discharge within insulators under the influence of aluminum impurities.