基于小波变换的配电网电压暂降的干扰源辨识

该文用EMTP建立了一个配电网电压暂降仿真系统，对线路故障引起的电压暂降以及多级电压暂降、变压器投运和感应电动机启动引起的电压哲降进行了原理分析并给出了相应的仿真结果。仿真分析结果表明：电压暂降的电压波形特征是和特定的干扰源相联系的，因此，可以利用它来辨识电压暂降的干扰源。在此基础上，文中提出了基于三次中心B样条小波变换的电压暂降干扰源辨识方法，该方法以电压暂降的电压波形为分析对象，以小波变换的奇异性检测理论为基础，利用B样条小波变换准确地提取了各种电压哲降的波形特征量，并对故障、变压器投运和三相感应电机启动引起的电压暂降做了辨识。仿真试验结果表明该方法简洁可靠，辨识准确性高，抗干扰能力强。

INTERFERENCE SOURCE IDENTIFICATION OF VOLTAGE SAG IN DISTRIBUTION SYSTEM BASED ON WAVELET TRANSFORM

Voltage sag due to line fault, transformer energizing and induction motor starting were analyzed based on an EMTP simulation model in this paper. The analysis results illustrate that characteristics of voltage sag is correspond to certain interference source. Based on these characteristics, a new interference source identification method is brought forward by using B spline wavelet transform. Using singularity theory of wavelet transform, voltage transform characteristics are extracted easily and accurately, so interference sources such as line fault, transformer energizing and induction starting, are identified at the same time. The results of simulation show this method is simple, accurate and applied.