基于矩阵束算法的XLPE电力电缆绝缘介质响应参数辨识

Parameter Identification for Dielectric Response of XLPE Power Cable Based on Matrix Pencil Algorithm

为解决交联聚乙烯(XLPE)电力电缆绝缘介质响应参数辨识中存在的问题,以便深入研究XLPE电力电缆绝缘老化与介质驰豫响应间的内在联系,提出一种基于矩阵束算法的扩展迪拜模型等效电路参数辨识方法。首先,利用去极化电流构建Hankel矩阵;然后对Hankel矩阵进行奇异值分解,根据奇异值曲线中奇异值大小判断信号子空间与噪声子空间并确定扩展迪拜模型驰豫支路数;最后利用确定的驰豫支路数对去极化电流进行极化参数辨识。仿真及实测结果表明:基于矩阵束算法的扩展迪拜模型等效电路参数辨识方法能够有效的对XLPE电力电缆绝缘介质响应函数进行驰豫支路数判断及参数辨识,即使在信号含噪较大时也能有效的对去极化电流进行重构。该等效参数辨识方法为评估XLPE电力电缆绝缘介质内部驰豫响应特性提供了准确可靠的数学诊断方法。

To solve the problems existing in parameter identification for dielectric response of XLPE power cable,so as to further study the inner link between aging condition of XLPE power cable and dielectric relaxation response,we put forward a method based on the matrix pencil algorithm to identify the equivalent circuit parameters of extended Debye model.Firstly,the Hankel matrix is created by the depolarization current.Then,singular value decomposition for the Hankel matrix is done to discriminate the signal subspace and noise subspace,and the number of equivalent circuit relaxation branches is identified by the singular value.Finally,the equivalent circuit parameters of depolarization current are identified using the number of relaxation branches.The simulation and experimental results show that the method can effectively identify the number of equivalent circuit relaxation branches and parameters of extended Debye model,and the method can reconstruct the depolarization current even with strong noises.The proposed method provides a correct and useful mathematical diagnostic model for evaluating the relaxation response performance of XLPE power cable.