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摘要: |
长期以来,比率制动曲线的比率制动部分历来都和电流互感器(TA)的抗饱和能力联系在一起,认为只要有了比率制动特性,差动保护就不会误动,但事实并非如此,长期统计表明有些原因不明的误动或多或少地和TA的暂态饱和有关,通过对非TPY级TA饱和的变压器区外故障动模数据分析,得出比率制动特性差动保护在P级TA暂态饱和情况下可能会误动的结论。同时,还详细阐述了选择合理的出口判据次数,数字滤波算法,数据窗的长度能提高差动保护抗TA暂态饱和能力的影响。 |
关键词: P级TA饱和 差动保护 电力系统 电网 继电保护 数字式比率制动特性 数字滤波 数据窗 |
DOI: |
分类号:TM772 |
基金项目: |
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Impaction of P-type CT saturation on digital ratio-restrained differential protection |
PU Nan-zhen 1 ZHAI Xue-feng 1 YUAN Yu-bo 2 LU Yu-ping 2
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Abstract: |
For a long time ,the ratio-restrained characteristic is assumed to avoid CT saturation and the differential protection with ratio-restrained characteristic is considered able to function properly.The statistical data indicate that some unknown malfunctions of differentia l protection may be caused by CT saturation.Through the dynamic simulation analysis of non-TPY-type CT saturation at out-area fault,it is concluded that the differental protection with ratio-restrained characteristic may function improperly under P-type CT transient saturation.The influence of trip judgment times,digital filter algorithm and data-window width on the ability against CT saturation is discussed. |
Key words: CT saturation,ratio-restrained characteristic,differential protection,digital filter,data window |