单电源线路纵差保护的灵敏度分析及改进

Sensitivity Analysis and Improvement for Longitudinal Differential Protection of Single Power Source Line

具有制动特性的单电源线路纵差保护在区内故障时，由于制动电流的影响，使其动作灵敏度较双电源时降低了２～３ 倍，很难满足灵敏度≥２ 的要求。通过采用其它保护（ＺⅢ、Ａ０Ⅲ、Ａ／Ｓ）闭锁的方式，可以降低纵差保护的整定值。

Because of the influence of braking current,the acting sensitivity during a fault within protection region of the longitudinal differential protection of single source line will decrease 2 3 times compared to that of double source line,and hence the sensiticity will not meet the requirment:≥2.By locking other protection equipments(Z Ⅲ,A 0Ⅲ ,A/S),the settings of longitudinal differntial protection can be reduced and the required sensitivity fulfilled.