一起穿越性故障导致的主变差动保护误动分析  

Analysis of Maloperation of Main Transformer Differential Protection Caused by a Through Fault

作　　者：王仁德 谢平强 Wang Ren-de;Xie Ping-qiang

机构地区：[1]国网湖南省电力有限公司邵阳供电分公司,湖南邵阳422000

出　　处：《电力系统装备》2022年第11期144-146,共3页Electric Power System Equipment

摘　　要：文章以一起穿越性故障导致的某110 kV变电站主变差动保护误动作为例,简要描述本次事故前后的变电站内的运行方式、保护动作情况及造成的影响;仔细分析了故障前主变高、低压侧电流相位关系,其相位关系与主变Y-Y-D-1接线方式下高、低压侧电流相位关系一致;主变变比组别测试验证了主变接线方式确为Y-Y-D-1接线方式,深入剖析了在该接线方式下,主变保护内部定值整定为Y-Y-D-11接线方式时,穿越性B、C相故障会导致主变A、C相差动保护动作的原因。Taking the maloperation of main transformer differential protection in a 110 kV substation caused by a through fault as an example,this paper briefly describes the operation mode,protection action and influence in the substation before and after the accident;The phase relationship of the current at the high and low voltage sides of the main transformer before the fault is carefully analyzed,and the phase relationship is consistent with the phase relationship of the current at the high and low voltage sides under the y-y-d-1 wiring mode of the main transformer;The ratio group test of main transformer verifies that the main transformer connection mode is y-y-d-1 connection mode,and deeply analyzes the reason why the through phase B and C fault will cause the phase A and C differential protection action of main transformer when the internal setting of main transformer protection is set to y-y-d-11 connection mode under this connection mode.

关 键 词：穿越性故障 变电站 变压器 接线方式 差动保护 

分 类 号：TM774[电气工程—电力系统及自动化]