配电系统单相接地全故障电流估算方法  

Estimation of Full Fault Current for Single-phase Grounding Fault of Distribution Power System

作　　者：李玉志[1] 林勇[1] 吴金玉[1] 唐敏[1] 晋飞[1] 

机构地区：[1]国网山东省电力公司潍坊供电公司,山东潍坊261000

出　　处：《山东电力技术》2015年第12期5-9,19,共6页Shandong Electric Power

摘　　要：配电系统发生单相接地故障时,故障点短路电流既包含工频分量,还包括持续时间较短、但在故障初期幅值较大、能量较为集中的暂态分量,快速、准确地计算出全故障电流是实现全故障电流补偿的前提。提出一种配电系统单相接地全故障电流的计算方法,采用等值Γ电路对系统线路建模,分析了采用Γ型等值电路进行计算的合理性和可行性,通过母线TV获取系统三相电压的时域信号,采用描述Γ电路的微分方程,基于KCL可计算出系统单相接地故障的全故障电流,此作为全故障电流的补偿依据。算例仿真表明基于等值Γ电路计算全故障电流的方法具有原理清晰、计算速度快、所需电气量少、计算结果准确、无需故障选线等优点,完全能够满足配电系统单相接地全故障电流补偿的要求。When the single-phase grounding fault in distribution power system occurs, the fault current includes not only the component of power frequency but also transient component with short duration ,large original amplitude and ~relatively concentrated energy.Rapid and accurate calculation of-the full fault current is the basis for realizing full fault current compensation.One method for full fault current calculation of single-phase grounding fault in distribution power system is proposed.Here F equivalent circuit is applied to model feeders, and the feasibility and rationality of that is analyzed.Then based on Kirchhoff current law and three phase time-domain voltage signals from bus TVs,the full fault current can be calculated via differential equations which are used to describe the F equivalent circuit.Calculation results can provide a basis for full fault current compensation.The simulation case indicates that the method used for calculating full fault current based on F equivalent circuit has advantages of discernible principle,rapid and accurate calculation,less electrical quantities needed and being independent of fault line selection.It can meet full fauh current compensation＇s demand of single-phase grounding fault in distribution power system.

关 键 词：配电系统 单相接地故障 等值Γ形电路 全故障电流估算 

分 类 号：TM773[电气工程—电力系统及自动化]