一种基于波形相关分析识别变压器励磁涌流的方法

提出了一种基于波形相关分析识别变压器励磁涌流的方法。该方法首先用线性插值法找出保护启动后最近的差流过零点,然后利用数字信号处理中相关函数的基本原理对采样数据进行分析,计算过零点后一周波中前后半波的自相关系数,根据自相关系数的大小构成区分励磁涌流和故障电流的主判据。动模试验结果表明该方法算法简单,原理清楚,识别正确,具有较高的可靠性和灵敏性。

A measure to identify the inrush current of transformer based on wave correlation analysis

A new scheme based on wave correlation analysis to distinguish the inrush and internal fault occurred in the transformer is proposed.Firstly, it is to find out the zero-crossing of the differential current using the linear interpolation method after the protection has enabled. Then it is to calculate self-correlation coefficients of the former semiwave and the backward semiwave after analyzing the sampling data. According to the magnitudes of the calculated coefficients, inrush current and fault current of transformer can be distinguished. The results of dynamic simulation verify the feasibility of the proposed method. Meanwhile, dynamic model test indicates that this algorithm has a simple calculation and its principle is clear.