基于磁通轨迹特征的变压器励磁涌流识别新方法

介绍了变压器保护正常动作率的现状,分析了当前比较流行的变压器励磁涌流判断方法,并指出缺陷。提出了一种基于磁通轨迹特征的变压器励磁涌流识别新方法,该方法根据变压器发生内部故障时铁心不饱和,而出现励磁涌流时铁心饱和的原理,利用实测的变压器电压和电流量推算变压器主磁通的轨迹,通过提取主磁通轨迹的特征来判断主磁通变化范围,从而确定变压器是否发生励磁涌流。仿真结果证明了识别方法的可行性。

Identification of transformer magnetization inrush current based on magnetic flux track

The correct operation rate of relay protection is presented,the current methods of magnetization inrush current detection are analyzed and the defects are pointed out.A method based on magnetic flux track is proposed.According to the principle that the internal fault will not cause core saturation while the magnetization inrush current does,the main magnetic flux track of transformer is calculated with measured voltages and currents and its characteristic is extracted to detect the magnetization inrush current according to the range of main magnetic flux variation.Simulation results verify the feasibility of the proposed method.