基于线性预测分析时差估计的特高频局部放电定位方法

UHF Partial Discharge Location Method Based on Time Delay Estimation of Linear Prediction Analysis

基于特高频(UHF)信号的局部放电(PD)定位方法由于其对信号时差的计算误差较大,因此还未能在变电站中进行广泛的应用。文中提出了一种基于线性预测分析的时差估计方法,该算法首先对实际采集的特高频信号做预测分析,然后对预测误差应用幂定律以突显局放发生时刻,最后利用广义相关法进行时差估计。该方法能够以较高的精度计算信号时差,从而提高了局放定位的精度。实验结果表明,利用文中方法进行局放定位,定位距离误差可控制在1 m以下,方向角定位误差可控制在8°以下,证明了该方法的可行性。

The localization of partial discharge(PD) based on ultra-high frequency(UHF)signals has not been widely used in substations due to the excessive localization error,which is mainly introduced by the error of time delay measurement.A novel time delay estimation method based on linear prediction analysis is proposed in this paper.Linear prediction analysis is carried out on the actual PD signals.The power law is applied to the prediction error to highlight the time of PD occurrence.Eventually,the generalized correlation algorithm is used to estimate the signal time delay.The proposed method could estimate the signal time delay with high precision,thus improving the accuracy of PD localization.Experiment results show that the localization distance error is less than 1 meter and the localization angel error is less than 8 degrees,which have proved the feasibility of this method.