| 黄海宏,金春阳,郝韩兵,刘 鑫.氧化锌避雷器泄漏电流的全相位 FFT 分析[J].电子测量与仪器学报,2021,35(7):210-216 |
| 氧化锌避雷器泄漏电流的全相位 FFT 分析 |
| All-phase FFT analysis for leakage current of zinc oxide arrester |
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| DOI： |
| 中文关键词: 氧化锌避雷器 谐波分析 全相位 FFT 校正算法 小信号 |
| 英文关键词:Zinc oxide arrester harmonic analysis all-phase FFT correction algorithm small signal |
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| 摘要点击次数: 377 |
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| 中文摘要: |
| 通过检测氧化锌避雷器泄漏电流,经过谐波分析提取泄漏电流基波和各次谐波参数,依据电流阻性分量可判断该装置
在电网中的运行情况。 为解决快速傅里叶变换(FFT)进行谐波分析时数据截断引起数字信号处理性能下降的问题,选用一种
考虑包含某样点所有可能数据截断情况的全相位 FFT 分析方法,再基于此分析方法选用全相位时移相位差校正算法,同时利
用窗谱函数推导出校正公式。 仿真结果表明,该算法对比基于 FFT 的比值公式校正算法在无噪和有噪(50 dB)情况下谐波分
析精度分别提高了 4~ 5 个数量级和 1~ 2 个数量级,且对相对小信号谐波分量的频率估计偏差不超过 0. 6 Hz,相位估计偏差不
超过 0. 5°。 该算法具有相位不变性和频谱泄漏抑制能力,实现了检测精度的提高和小信号参数的估计,并在泄漏电流检测系
统中得到验证。 |
| 英文摘要: |
| The detection of the leakage current of the zinc oxide arrester is achieved by extracting the fundamental and harmonic
parameters of the leakage current through harmonic analysis, and the operation of the device in the power grid can be judged according to
the resistive component of the harmonic current. In order to solve the problem of digital signal processing performance degradation caused
by data truncation during harmonic analysis by fast Fourier transform (FFT). All-phase FFT analysis method that considers all possible
data truncation conditions of a sample point is selected, and then all-phase time-shift phase difference correction algorithm is selected
based on this analysis method, and use the window spectrum function to derive a correction formula. Compared with the ratio correction
algorithm based on FFT, the algorithm which is selected has improved the accuracy of harmonic analysis by 4 to 5 orders of magnitude in
the case of no noise and 1 to 2 orders of magnitude in the case of noisy (50 dB), and the frequency estimation deviation for relatively
small signals does not exceed 0. 6 Hz, and the phase estimation deviation does not exceed 0. 5°. This algorithm has phase invariance and
better ability to suppress spectrum leakage and realizes the improvement of detection accuracy and the estimation of small signal harmonic
parameters, which is verified in the leakage current detection system. |
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