基于宽带相干信号模型的局放超声波定位研究

Research on Ultrasonic Location of Partial Discharge Based on Broadband Coherent Signal Model

传统算法在实际工程中对相干信号的局部放电(局放)源定位精度一般,分辨率也较低。分析了双局放源到传感器的距离差值与局放超声波信号相关系数的关系,提出了一种针对宽带相干模型局放信号的修正MUSIC算法(MMUSIC)与ISM相结合的降维DOA估计算法,并通过MATLAB将两个相干的局放信号和两个不相干的局放信号进行研究对比,证明该算法的有效性。将该算法应用到实验中,结果表明对相干信号和非相干信号的测向误差在9°左右,满足工程实际需要。

The traditional algorithm has low accuracy and low res in locating the partial discharge point source of the coherent signal.This paper analyzed the relationship between the distance difference of dual partial discharge sources to the sensor and the related coefficient of the ultrasonic signal of partial discharge.It proposed a dimension reduction DOA estimation algorithm that combined the modified MUSIC algorithm (MMUSIC) and ISM for the partial discharge signal of the broadband coherent model.In addition,this research compared and studied the situation of two coherent partial discharge signals and the situation of two incoherent discharge signals by using MATLAB software.The result showed that this algorithm is effective.This study has applied the algorithm to the experiment.The result shows that the direction-finding error of the coherent signal and the incoherent signal is around 9°,which meets the practical needs of engineering.