【摘要】 为研究变压器在线监测的关键问题局部放电(PD)的识别和定位,提出了用单个电磁矢量传感器(即EM-VS,它能同时测量入射电磁波的全部电磁场分量,其测量数据可实现对入射波空间参数的极化特性的估计)检测局部放电辐射超高频信号来实现变压器局放定位的方法,该法先将检测的PD宽带数据通过窄带滤波,获取相应的窄带数据,并应用信息论的最小描述长度准则或平滑秩序列法确定PD源个数后应用多重信号分类算法对数据协方差矩阵进行空间谱估计,实现多个局放源点分辨和空间参数估计。仿真实验结果表明,单个EMVS可同时检测出3个局放源点的方位角、俯仰角及其极化特性,对变压器局部放电在线检测和状态估计具有较高的参考价值。更多还原

【Abstract】 Partial discharge(PD) sources identification and orientation is one of the key problems for PD online monitoring of transformers.Electromagnetic vector sensor(EMVS) has been successfully applied to estimate the electromagnetic sources’ spatial parameters and polarizations.In this paper,a single EMVS is proposed to measure the ultra-high frequency(UHF) signal for PD detection and orientation.With its output data processed by a narrowband filter,the number of PD sources can be estimated exactly by using minimal describing length(MDL) rule or smoothed rank sequence(SRS) method.Based on which,the spatial parameters and polarizations of PD sources can be obtained by adopting MUSIC algorithm to estimate the spatial spectrum of the data’s covariance matrix.The results of simulate experiment show that this method is capable of identifying three PD sources and estimating their azimuth,elevation and polarization.It is practical and hopeful to realize the PD orientation in transformer online PD monitoring.更多还原