半波傅氏算法与两点乘积算法相结合的励磁涌流识别新方法  

New algorithm to identify inrush current based on half-wave fourier and two points product method

作　　者：陈达壮[1] 张玲 

机构地区：[1]华北电力大学电气与电子工程学院,河北保定071003 [2]福建省厦门电业局,福建厦门361004

出　　处：《电力系统保护与控制》2010年第17期138-141,共4页Power System Protection and Control

摘　　要：为解决变压器差动保护由于励磁涌流而经常误动的问题,针对励磁涌流波形畸变严重且会出现尖顶波,而故障电流基本保持基频正弦波特征的特点,以半波傅氏算法为基础,提出了两点乘积算法来识别变压器励磁涌流的新方法。该方法先通过差分滤波得到差动电流,用半波傅氏算法求得其基波实部,利用三角函数定理,求得多组相邻π/2两电流的平方和,然后比较相邻两组平方和的比值来判断励磁涌流。通过对动模试验数据的分析计算验证了本方法的正确性和有效性。A new algorithm based on half-wave fourier and two points product method is presented for solving the mal-operation in transformer differential protection due to magnetizing inrush current.The method is based on the principle that the waveform of the inrush distorts seriously and even forms into vertex sharp wave,while the fault current keeps nearly sinusoid. Based on the half-wave fourier,this method samples currents with differential filter continuously,gets groups of square sum of two neighboring PI/2 currents using trigonometric theorem,then distinguishes inrush current by the ratios of neighboring groups of square sum.Theoretical analysis and dynamic simulation results show that the method is correct and effective under various fault conditions.

关 键 词：差动保护 励磁涌流 半波傅氏算法 两点乘积算法 三角函数 

分 类 号：TM773[电气工程—电力系统及自动化]