用相关函数原理识别变压器励磁涌流.pdf

文档介绍：第 29 卷第 6 期电网技术 Vol. 29 No. 6
2005 年 3 月 Power System Technology Mar. 2005
文章编号:1000-3673(2005)06-0078-04 中图分类号:TM772 文献标识码:A 学科代码:470×4054
用相关函数原理识别变压器励磁涌流
和短路电流的新方法
马静,王增平,徐岩
(华北电力大学电气工程学院,河北省保定市 071003)

A NEW METHOD TO IDENTIFY INRUSH CURRENT AND SHORT CIRCUIT CURRENT
OF TRANSFORMER BASED ON CORRELATION FUNCTION
MA Jing,WANG Zeng-ping,XU Yan
(School of Electrical Engineering,North China Electric Power University,
Baoding 071003,Hebei Province,China)
ABSTRACT: When longitudinal differential protection is 的矛盾;二是正确识别励磁涌流和内部故障时的短
applied to transformer protection, how to identify the inrush 路电流。现场运行的绝大部分电力变压器均采用纵
current and short circuit current caused by internal fault is the 联差动保护作为主保护以解决前一个问题,因此关
key problem. Here, regarding the inrush current and short
键问题是如何正确识别励磁涌流和短路电流。
circuit current as the random signal, the sampled data are
现场运行的变压器差动保护主要采用二次谐
analyzed by correlation function principle in the digital signal
processing and the self-correlation function of the sampled data 波制动原理和间断角原理来识别励磁涌流,其中二
is calculated. Through the parison operation 次谐波制动原理应用最为广泛。但电流互感器的饱
conducted by standard self-correlation function formed with 和及用于无功补偿的并联电容或超高压长输电线
sinusoidal current the short circuit current and the inrush 分布电容的存在,使得变压器发生内部故障时也会
current can be distinguished by the magnitude of similarity 产生很大的二次谐波,而且变压器铁心材料的改进