电流互感器N相断线对主变差动保护动作的影响分析

Analysis of Influence of Current Transformer N Phase Break Line on Differential Protection Action of Main Transformer

文章立足于一次由于电流互感器N相断线造成主变差动保护误动作的电力系统事件。结合事件报告及故障录波图分析该事件的直接原因,根据装置差流归算法则建立电流互感器N相断线后差流计算的模型,利用模型模拟事件发生的过程,从理论上验证该事件的分析结果。最后通过同一归算法则的实验装置还原事件过程,从实际上验证模型及分析结果的正确性。

This paper is based on an electric power system event caused by differential protection of main transformer malfunction due to the current transformer N phase break line.It analyzes the direct cause of the event combined with the event report and fault recording wave diagram,establishes the model of differential current calculation after current transformer N phase break line according to the device differential current return algorithm,uses the model to simulate the occurrence process of the event,and verifies the analytic result of the event theoretically.Finally,the event process is restored through the experimental device of the same return calculation rule to verify the correctness of the model and analytic result practically.