基于小波变换的电缆局部放电定位中时延算法研究

Study on Time Delay Estimation Algorithm in Cable Partial Discharge Location Based on Wavelet Transform

在电缆局部放电定位直接相关法的基础上,研究出了一种基于小波变换的广义相关时延估计算法。此算法放宽了直接互相关法对信号与噪声的假设条件且在低信噪比下仍能有效估计时延;同时为了提高时延估计精度,在广义相关时延估计的基础上又研究出了基于基小波的二次加权法。利用PSCAD/EMTDC仿真分析论证了这两种算法在电缆局部放电定位中的有效性。

Based on direct correlation method and wavelet transform, a general correlation time delay estimation algorithm was proposed. It extended the assumed condition of direct cross-correlation for signal and noise, and was capable to estimate time-delay effectively under low signal noise ratio. Moreover, a base-wavelet based twice-weighted method was proposed to improve the accuracy of time-delay estimation. Using PSCAD/EMTDC to emulate the cable patrial discharge location, simulation results validated the two algorithms.