变压器励磁涌流对差动保护的影响及解决方法

当变压器空载投入或外部故障切除后,由于电压的恢复,出现很大的励磁电流,其值可达6-8倍的额定电流。这种暂态过程中出现的励磁电流称为励磁涌流。励磁涌流是另一种形式的暂态不平衡电流,它经变压器电源侧电流互感器传到二次侧,如流入差动回路,往往会导致差动保护误动作。这就需要分析励磁涌流产生的原因、励磁涌流对变压器差动保护的影响及解决方法进行探讨。

After the removal of the transformer no-load input or external fault, voltage recovery, the excitation current, and its value up to 6-8 times the rated current. The excitation current in such a transient process called inrush current. Magnetizing inrush is another form of transient current imbalance, and it spread through the transformer power supply side current transformer secondary side, such as the inflow of the differential circuit, often lead to differential protection malfunction. This requires analysis of the magnetizing inrush current causes of magnetizing inrush current of transformer differential protection and solutions to explore.