利用故障特征频带和TT变换的电缆单端行波测距

A Single Terminal Cable Fault Location Method Based on Fault Characteristic Frequency Band and TT Transform

与架空线路相比,电缆线路行波色散更为严重,其行波波速度的确定及故障行波波头到达时刻的精确标定更为关键。将单端行波暂态信号进行小波分解并重构为多个频带的时域信号,采用相关分析计算每一个频带下2个波头的相关系数,选择相关系数最大的频带为特征频带,并利用特征频带的中心频率计算电缆行波波速。在特征频带内利用时域变换的TT算法,对行波波头到达量测端的时刻进行精确标定。由此构建了基于故障特征频带和TT变换的电缆线路单端行波测距方法。大量高压电缆故障测距的电磁暂态仿真结果表明,该方法有效,测距精度高。

Because the traveling-wave dispersion of cable is more serious compared with overhead lines,determining the traveling wave speed and accurate arrival time calibration of fault traveling wave surge is more important for fault location of cable lines.In the paper,a single terminal traveling wave fault location method based on wavelet transform and TT transform was proposed.Fault-generated transient current signals were decomposed by wavelet decomposition transform（WDT） and the decomposition signal was reconstructed into multiple bands of the time-domain signal.In each band,the correlation coefficient of the two wave heads was calculated by the correlation analysis.The largest correlation coefficient of the band was selected as the characteristic band.The center frequency of the characteristic band was used to calculate the traveling wave speed.In the selected frequency bands,the time-time transform（TT algorithm） was used to determine the arrival time of the wave front of fault traveling wave.A large number of electromagnetic transient simulations for high voltage cable fault location indicate that the method is effective and has high accuracy.