| 邢毓华,魏子薇.MFWVD时频分析在时延估计中的研究与应用[J].电子测量与仪器学报,2025,39(2):240-250 |
| MFWVD时频分析在时延估计中的研究与应用 |
| Research and application of MFWVD time-frequencyanalysis in delay estimation |
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| DOI： |
| 中文关键词: 时延估计 时频分析 魏格纳威利分布 交叉项干扰 时频互相关 电缆故障定位 |
| 英文关键词:delay estimation time-frequency analysis Wigner-Ville distribution cross-term interference time-frequency cross-correlation cable fault location |
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| 摘要点击次数: 14 |
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| 中文摘要: |
| 针对常见时频分析中存在交叉项干扰或时频聚焦度较低而无法准确进行时延估计的问题，提出一种遮罩滤波魏格纳威利分布时延估计新方法。其基本原理是将WVD时频谱与SPWVD时频谱的幅度谱之比同高斯函数滤波器相结合,利用SPWVD方法能够有效抑制交叉项干扰和WVD方法时频聚焦度高的优点，将信号的SPWVD时频谱作为一个遮罩以此屏蔽WVD时频谱中的交叉项，在保持高时频分辨率的同时获得高精度的时频谱。该方法与常见时频域反射方法相比在交叉项抑制和时频聚焦度这两个关键性能指标上具有更好的性能，时延估计结果的可靠性较高。利用该方法结合时频互相关函数定位电缆微弱的低阻故障，通过仿真实验进行对比分析，结果显示所提方法在定位电缆1.5 km处的低阻故障时，均方根误差为0.652 7 m，与WVD方法和SPWVD方法相比，定位误差分别减少了1.288 4和0.683 4 m。此外，该方法在信噪比为-5、0和5 dB的情况下定位误差均小于其他常见方法，定位效果最佳。 |
| 英文摘要: |
| A new time delay estimation method based on masked filtering Wigner-Ville distribution is proposed to address the issues of cross-term interference or low time-frequency concentration in common time-frequency analysis, which lead to inaccurate time delay estimation. The basic principle is to combine the amplitude spectrum ratio of the WVD time-frequency spectrum and the SPWVD time-frequency spectrum with a Gaussian function filter. By taking advantage of the SPWVD method’s ability to effectively suppress cross-term interference and the high time-frequency concentration of the WVD method, the SPWVD time-frequency spectrum of the signal is used as a mask to shield the cross-terms in the WVD time-frequency spectrum, thereby obtaining a high-precision time-frequency spectrum while maintaining high time-frequency resolution. Compared with common time-frequency domain reflection methods, this method exhibits better performance in two key performance indicators, namely cross-term suppression and time-frequency concentration, and the reliability of the time delay estimation results is relatively high. This method is applied to locate weak low-resistance faults in cables in combination with the time-frequency cross-correlation function. Through comparative analysis of simulation experiments, the results show that when locating a low-resistance fault at 1.5 km in the cable, the root mean square error of the proposed method is 0.652 7 m. Compared with the WVD method and the SPWVD method, the positioning errors are reduced by 1.288 4 and 0.683 4 m respectively. In addition, the positioning error of this method is smaller than that of other common methods under signal-to-noise ratios of -5、0, and 5, and the positioning effect is the best. |
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