基于线路两端电压间夹角的三相故障开放判据  

A Novel Power System Swing Unblock Criterion of Three-phase Faults for High Voltage Line Protection Relay Based on the Voltage Phase Angle of Two Terminals of the Line

作　　者：刘凯[1,2] 索南加乐[1] 

机构地区：[1]西安交通大学电气工程学院,陕西省西安市710049 [2]东方电子集团有限公司,山东省烟台市264001

出　　处：《电力系统自动化》2010年第7期66-69,共4页Automation of Electric Power Systems

基　　金：国家自然科学基金资助项目(50677051)~~

摘　　要：线路两端电压间夹角反映线路两侧电源之间的电势角差,系统振荡时该角度周期性变化,变化周期与振荡周期相同;线路上发生三相故障时,该角度稳定为180°。基于此特征,提出了一种新的线路保护振荡中三相故障开放判据。在一个较短时间内,可以认为振荡是匀速的,根据线路两端电压间夹角相对于时间的变化率,可以推测该角度在180°左右的较小角度区间内停留的时间,如果该角度停留在180°左右超过推测时间,可确认发生了三相故障,并开放保护。新判据可以实时根据振荡速度确定开放时间,与振荡周期自适应,该判据加快了振荡中三相故障的切除速度。动模数据仿真验证了该判据的有效性。A novel power system swing unblock criterion of the three-phase faults for the high voltage line protection relay is presented.Through the voltage and current,the protective relay obtains the line impedance parameter,and the voltage of another terminal of the line can then be calculated.The angle between the phasors of the sampled voltage and the calculated voltage changes periodically when the power system swings,and when there is a three-phase fault occurring on the line,this value of the angle is 180° and does not change,according to such a character,a new three-phase fault unblock criterion is presented.The criterion can determine the unblock delay by the actual swing period,easy to use in the current relay device.

关 键 词：线路保护 振荡闭锁 自适应 开放判据 

分 类 号：TM755[电气工程—电力系统及自动化]