基于S变换模能量分析的直流电缆故障测距

Fault Location of DC Cable Based on S-transform Mode Energy Analysis

针对现有高压直流电缆故障定位方法故障定位精度低、定位模型泛化能力差等问题,文中在考虑电缆故障后故障点产生的暂态信号中含有丰富的故障信息的特征,提出一种时频域能量分析的故障测距方法。该方法利用多分类支持向量机(SVM)的特性构建直流电缆故障定位模型,利用直流电缆相模解耦矩阵对电缆电气量解耦,并采用S变换进行时频域变换,将得到的模量构造模能量,将其作为样本对SVM模型训练。实验结果表明,所提方法对于不同故障类型在不同过渡电阻及不同位置故障下均可进行准确测距。

In view of such issues as low accuracy of fault location and and weak generalization ability of location model in the fault location method of existing high voltage DC cable,a kind of fault location method of time-frequency domain energy analysis is proposed with consideration of the characteristics of rich fault information in the transient signal generated by the fault point after the fault of the cable.The method uses the characteristics of multi-class support vector machine to construct a DC cable fault location model,uses the DC cable phase mode decoupling matrix to decouple the electrical parameters of the cable,and adopts the S-transform to perform time-frequency domain conversion.The obtained modulus is used to construct mode energy and is used as the sample to trains the SVM model.The experimental results show that the proposed method can accurately measure the distance of different types of faults under different transition resistances and different locations.