线路断线引起220kV变电站主变压器故障分析及处理措施

乌海电业局220 kV顺达变电站110 kV线路(159)保护动作跳闸,同时220 kV 1号主变压器差动保护动作跳闸。经检查分析,159线路导线因处在空气重污染地区,长年受污染物腐蚀,在导线拉力及微风振动作用下钢芯铝绞线减薄、断裂,引起单相接地短路,产生的零序电流流经1号主变压器线圈及中性点,在10 kV平衡绕组中产生较大环流。在该电流冲击下,变压器平衡绕组产生的电动力导致绕组发生严重变形,进而形成匝间短路并对铁心放电,最终1号主变压器差动保护动作。将1号主变压器返厂进行解体修复,运回现场安装、试验合格后,至今运行正常。

Analysis and Treatment Measures of 220 kV Substation Main Transformer Fault Caused by Transmission Line Breakage

The 110 kV line （159） relay tripped in Shunda 220 kV Substation of Wuhai Electric Power Bureau, at the same time No. 1 220 kV main transformer differential protection tripped. After checking and analysis, 159 lines were in the heavy air pollution area, affected by pollutants corrosion all the year round, ACSR were thinning or fracture in the role of wire tension and the breeze vibration, caused single phase grounding fault, zero sequence current flowing through the No. 1 main transformer eoil and neutral point, produeed large eireulation in the 10 kV balance winding. In the eurrent shock, electric power eaused by balanee winding of the transformer winding lead to serious deformation, and the formation of inter turn short eireuit and the diseharge to core, finally the No. 1 main transformer differential protection acted. No. 1 main transformer was repaired back to factory for disintegration through installation and test, operation was normally.