采用自适应数据窗电流的励磁涌流鉴别方法

发布时间：2018-03-31 00:34

本文选题：差动保护　切入点：变压器　出处：《中国电机工程学报》2014年04期

【摘要】：为进一步提高励磁涌流鉴别的速度及精度,尤其是快速检测出带故障合闸时的涌流,使该情况下保护的开放时间缩短至一个周期内,提出一种采用自适应数据窗电流的励磁涌流鉴别方法。该方法在时间轴上下分别设置阈值??,利用该阈值及某段采样电流的极大值或极小值,确定出自适应数据窗的起点及终点;并在选取出的自适应数据窗内,根据采样间隔及数据窗长度,以此极值向左向右虚拟出一条标准正弦曲线,计算出该正弦曲线与原采样电流之间的相关系数,进而实现保护的闭锁和开放。相比先前励磁涌流鉴别方法,该方法能够更大程度地区分出涌流及故障电流,在变压器发生励磁涌流时,结合所提出的辅助加速闭锁判据,算法最迟在空载合闸后一个周期时闭锁差动保护;在内部故障时不误闭锁差动保护;还能在变压器带故障空载合闸时,快速开放差动保护;且具有较强的抗互感器饱和能力。动模试验验证了该方案的有效性及优越性,在变压器带1.7%匝间短路故障空载合闸时,算法于合闸后20 ms开放差动保护。
[Abstract]:In order to further improve the speed and precision of inrush identification, especially the rapid detection of the fault of the closing current, so that the time of opening protection is shortened to a period, a self-adaptive data window current inrush current identification method. This method is set on the time axis respectively under the threshold?? the current sampling, threshold and a maximum or minimum value, to determine the starting point and end point adaptive data window; and the adaptive data window selected, according to the sampling interval and the length of data window, on the extreme left and right simulate a standard sine curve, calculate the sine curve with the original sample the correlation coefficient between the current, so as to realize the protection of the locking and opening. Compared with previous inrush identification methods, this method can better discriminate between inrush and fault current in transformer excitation occurs The magnetic inrush current, auxiliary acceleration blocking criterion combined with the proposed algorithm, the latest in a period when no-load closing after locking differential protection; in the internal fault not maloperation of differential protection; also with fault in the transformer no-load closing, fast open differential protection; and has strong anti transformer saturation capacity. Model test to verify the validity and superiority of the scheme, with 1.7% in transformer interturn short circuit fault when no-load closing, closing algorithm to the open differential protection after 20 ms.

【作者单位】：东南大学电气工程学院;
【基金】：国家自然科学基金项目(50977012,51377022)~~
【分类号】：TM774

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