城市电网35kV系统单相接地故障分析  

The Fault Analysis of 35 kV System Single-phase Grounding in Urban Grid

作　　者：金英 

机构地区：[1]上海电力公司市区供电公司,上海200080

出　　处：《东北电力技术》2013年第2期32-36,47,共6页Northeast Electric Power Technology

摘　　要：35 kV系统通常采用小电阻接地,35 kV接地变共有两种接入方式,即接地变接在35 kV母线上和接在主变35 kV侧,接入方式不同,零序保护配置也不同。因此,利用对称分量法,分析零流保护的配置及在不同地点单相接地时零流保护动作情况。详细分析了当保护或开关拒动时,各级零流保护配合动作情况,为电网调度员正确及时处理35 kV系统单相接地事故提供了一个清晰的思路。In the city power grid 35 kV system, single-phase grounding is a common fault, and zero sequence current protection is installed to eliminate it. The 35 kV system usually adopts the grounding transformer with small resistance neutral grounding mode. There are two ways for the connecting of the grounding transformer, one is connected to the 35 kV bus bar, and the other is a connection in the transformer 35 kV side. If the ground access is in different, the zero sequence current protection configurations are also different. According to the two 35 kV ground access, using the method of symmetrical components, this article analyses of zero sequence current protection configuration, and also analyses zero sequence current protection action on different the single-phase grounding fault. Especially, how the levels of zero sequence current protection act when the protecting or switch malfunction. Through the detailed analysis, it will good for the power grid dispatchers to correct and timely treatment of single-phase grounding accident in 35 kV system.

关 键 词：小电阻接地系统 单相接地 零序电流 零流保护 接地变 对称分量法 

分 类 号：TM727.2[电气工程—电力系统及自动化] TM862