基于非饱和区域波形相关分析的励磁涌流鉴别方法  

Correlation Analysis of Waveforms in Non-saturation Zone Based Method to Identify Magnetizing Inrush in Transformer

作　　者：毕大强[1] 张项安 杨恢宏 余高旺 王祥珩[1] 王维俭[1] 

机构地区：[1]清华大学电机系电力系统国家重点实验室,北京市100084 [2]许继电气保护及自动化事业部,河南省许昌市461000

出　　处：《电力系统自动化》2006年第6期16-20,24,共6页Automation of Electric Power Systems

基　　金：国家自然科学基金资助项目(50507014)许继电力科技基金资助项目。~~

摘　　要：提出一种基于波形相关程度鉴别变压器励磁涌流与故障电流的新方法。该方法通过比较动态差流短数据窗内各采样点代数和的大小,寻找出励磁涌流或短路故障下变压器的非饱和区域,由非饱和区内采样数据的最大值及其位置构造出2种形式的标准正弦波,再分别计算非饱和区内差流采样波形与2种构造正弦波的相关程度,根据相关系数平均值的大小区分励磁涌流与故障电流。动模试验结果分析表明,该方法在变压器运行中发生内部故障以及带故障空载合闸时,能够快速开放纵差保护;在空载合闸发生励磁涌流时,能够可靠闭锁纵差保护,并且能够实现分相闭锁,具有较好的抗电流互感器饱和能力。A novel algorithm based on the correlation analysis of waveforms to distinguish between magnetizing inrush and short-circuit fault current is proposed. In the proposed algorithm, the non.saturation zone of transformer is decided by comparing the algebraic sum of sampling data in a short slide window of differential current under magnetizing inrush and short circuit fault, then two kinds of standard sinus（tidal waveform are structured according to the value and position of peak point of differential current in the non-saturation zone. The correlation coefficients between the sampling waveform and two structured sinusoidal waveforms are calculated, and the magnetizing inrush or fault current is decided according to the average of correlation coefficients. Experimental results verify that the method can correctly switch on the differential protection in short time for the internal short circuit fault in operation and energizing with turn to turn short circuit, and reliably block the protection during the magnetizing inrush. The method can block the differential protection in split-phase, and is of good capability being immune to the saturation of current transformer.

关 键 词：变压器 饱和 励磁涌流 故障电流 

分 类 号：TM407[电气工程—电器]