|
| 摘要: |
| 在等效电路的基础上,从磁链变化的角度出发,对变压器外部故障切除的暂态过程进行了详细的理论分析,并给出相应的关系式,指出:变压器外部故障切除后的铁芯磁链包含2个直流衰减分量,正是这2个直流衰减分量与稳态量的共同作用使得变压器铁芯在外部故障切除后出现饱和,导致恢复性涌流的产生。同时,在利用分段线性特性考虑磁化特性的情况下,通过数值仿真的方法证明:负荷支路的存在使得变压器一次侧电流在外部故障切除产生电压恢复性涌流后的涌流波形特征不明显,且电压恢复性涌流中的二次谐波含量可能较小,从而对变压器差动保护及电流保护造成影响,有可能导致其误动作。 |
| 关键词: 变压器,恢复性涌流,差动保护,误动 |
| DOI： |
| 分类号:TM772 |
| 基金项目:国家自然科学基金资助项目(90610024,50467002,50347026)，云南省自然科学基金资助项目(2005F0-005Z,2004E0020M,2002E0025M)，云南省科技攻关项目(2003GG10)~~ |
|
| Research on recovery inrush in operating transformer |
|
LI Li-xin SHU Hong-chun
|
| Abstract: |
| Based on the transformer equivalent circuit,the transient process during the isolation of transformer external fault is analyzed according to flux variation and the corresponding formula is obtained. It is pointed out that,the main flux of the transformer consists of two exponentially decaying DC components,which,together with the steady component,cause the transformer saturated and the recovery inrush produced. Considering the piecewise magnetization characteristics are linear,nu-merical simulation proves that,the feature of recovery inrush is not obvious because of the existing load branch and its small secondary harmonic,which may lead to the misoperations of transformer differential protection and current protection. |
| Key words: transformer,recovery inrush,differential protection,misoperation |
