微机保护中TA饱和检测的算法研究

TA Saturated Examination Algorithm in Microcomputer Protection

阐述了TA饱和对母线差动保护的影响,利用小波变换能对奇异点进行准确分析定位的原理,提出了一种实时检测TA饱和区和线性区的新方法。该方法在故障开始后对TA二次电流实时进行多尺度小波变换,根据TA二次电流波形在故障发生时进入饱和时刻和出饱和时刻都有奇异性,并分别对应小波模极大值,而小波模极大值的不同特征判断对应进饱和点和出饱和点。用三次B样条函数仿真实践检测判据,证明了其有效性。

The influence of TA saturation on the bus differential protection was discussed , and a new method for real-time detection of TA saturated zone and linear area was proposed according to the principle that wavelet transform can position the singular point accurately . Real time multi-scale wavelet transform to TA secondary current was carried on after the fault occurred using this method. The criteria was tested with B-spline simulation and its effectiveness was proved.