TA饱和导致变压器差动保护误动作研究

Study on Differential Protection Misoperation of Transformer Caused by TA Saturation

变压器差动速断保护作为差动比率保护的补充,在变压器发生严重区内故障时能够快速切断故障,防止事故范围的扩大。由于故障电流中的衰减非周期分量,可能导致TA饱和不能正确传动电流,使得差动速断保护误动作。以一起典型的变压器区外故障情况下由TA饱和导致的差动速断保护误动作为例,介绍该事故发生的原因与过程,研究TA传变特性数学建模及影响TA饱和的因素,针对性提出预防此类问题出现的建议措施,保护电网的安全稳定运行。

As a supplement of differential ratio protection,transformer differential quick-break protection can quickly cut off the serious fault in the area of transformer and prevent the expansion of the accident range.Due to the decaying aperiodic component in the fault current,TA saturation probably cannot drive the current correctly,resulting in the misoperation of differential quick-break protection.This paper takes as an example the misoperation of differential quick-break protection caused by TA saturation under a typical fault outside the transformer area,introduces the causes and process of the accident,and makes studies on the mathematical modeling of TA transmission characteristics and the factors affecting TA saturation.Finally,the paper puts forward suggestions and measures to prevent such problems,so as to protect the safe and stable operation of the power grid.