A New Adaptive Method to Identify TA Saturation Using Grille Fractal
A New Adaptive Method to Identify TA Saturation Using Grille Fractal
复制标题
DOI：
10.1109/cjece.2014.2303518
复制
发表时间：
2013-01
期刊：
影响因子：
--
通讯作者：
Jing Ma;Xiang Gao;Zengping Wang;Qixun Yang
中科院分区：
文献类型：
--
作者：
Jing Ma;Xiang Gao;Zengping Wang;Qixun Yang
分析了Transformer差动保护在电流互感器Transformer饱和状态下，区内故障和区外故障时差动电流的不同奇异性特征。提出了一种利用栅格分形防止Transformer差动保护误动的新方法。将该方法与自适应广义形态滤波器相结合，可以充分保留信号的奇异性特征。同时，可以抑制噪声和干扰。该方法不需要精确地确定故障发生和差动电流出现的时刻。利用最大值平滑域和最小值平滑域的相对大小，通过设置适当的阈值，可以可靠地识别出Transformer内部故障，且识别不受励磁涌流的影响。此外，可以可靠地识别演化故障。动态仿真结果证明了该方法的有效性和可行性。
In this paper, the different singularity characteristics of differential current of transformer differential protection under inner-zone and out-zone faults are analyzed while the current transformer is saturated. Then, using grille fractal, a new approach to prevent maloperation of transformer differential protection is proposed. Combining the proposed approach with an adaptive generalized morphological filter, the singularity characteristic of the signal can be fully reserved. Meanwhile, noises and interferences can be restrained. It is not necessary for the proposed approach to accurately determine the moment when fault occurs and differential current appears. Using relative magnitude of smooth domain of maximal value and that of minimal value and by means of setting an appropriate threshold, the inner fault of the transformer can be reliably identified and the identification is not affected by inrush current. Besides, the evolved fault can be reliably identified. Results of dynamic simulation prove that the proposed approach is effective and feasible.