Spectral interpolation measurement algorithm of high accuracy on signals in power network
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摘要: 在非同步采样条件下,利用快速傅里叶变换算法分析电网谐波时将出现由长范围频谱泄漏、短范围频谱泄漏、负频点频谱泄漏等造成的测量误差.为了提高测量准确度,推导了频谱泄漏误差的表达式.针对工频交流正弦信号,提出了一种能够同时消除短范围频谱泄漏和负频点频谱泄漏的插值算法.仿真结果和实际的测量实验结果表明:与已有的插值算法相比,所提算法不需要对信号施加特殊的窗函数,在非同步采样程度较大的情况下,利用较少的采样样本便可准确地获得信号的频率、幅值和相位,适用于对准确度要求很高的精密测量领域.Abstract: In the condition of asynchronous sampling, the long-range spectral leakages, short-range spectral leakages and negative frequency spectral leakages will be caused by using Fourier transforms to analyze the harmonics in power network. To improve the measurement accuracy, the spectrum leakage error expressions were derived. For power frequency alternating current signals, a new error correction algorithm based on interpolation was presented to eliminate both of the short-range spectral leakage errors and the negative frequency spectral leakage errors at the same time. Compared with the previous interpolation algorithms, the simulations and practical measurements show the new algorithm need not weight the samples by special windows and can measure out the accurate frequency, amplitude and phase of the signals even if the asynchronous sampling is very serious. It is applicable for the precise measurement fields requiring a higher accuracy.
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Key words:
- Fourier transforms /
- asynchronous sampling /
- leakages /
- interpolation /
- measurement error
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[1] 刘琼章,张征平,陈艳峰.电力信号相位差测量方法之探讨[J].电测与仪表,2004,41(6):17-20 Liu Qiongzhang,Zhang Zhengping,Chen Yanfeng.A discussion about the measurement methods of power signals phase difference [J].Electrical Measurement & Instrumentation,2004,41(6):17-20(in Chinese) [2] 吴静,赵伟.适用于非同步采样的相位差准确测量方法[J].电网技术,2006,30(7):73-76 Wu Jing,Zhao Wei.A new accurate measuring method of phase difference suitable for asynchronous sampling[J].Power System Technology,2006,30(7):73-76(in Chinese) [3] Jain V K,Collins W L,Davis D C.High-accuracy analog measurements via interpolated FFT[J].IEEE Trans on Instrum Meas,1979,28(2):113-121 [4] Santamaria-Caballero I,Pantaleon-Prieto C J,Ibanez-Diaz J,et al.Improved procedures for estimating amplitudes and phases of harmonics with application to vibration analysis[J].IEEE Trans on Instrum Meas,1998,47(1):209-214 [5] 张伏生,耿中行,葛耀中.电力系统谐波分析的高精度FFT算法[J].中国电机工程学报,1999,19(3):63-66 Zhang Fusheng,Geng Zhongxing,Ge Yaozhong.FFT algorithm with high accuracy for harmonic analysis in power system[J].Proceedings of the CSEE,1999,19(3):63-66(in Chinese) [6] 庞浩,李东霞,俎云霄,等.应用FFT进行电力系统谐波分析的改进算法[J].中国电机工程学报,2003,23(6):50-54 Pang Hao,Li Dongxia,Zu Yunxiao,et al.An improved algorithm for harmonic analysis of power system using FFT technique[J].Proceedings of the CSEE,2003,23(6):50-54(in Chinese) [7] 江亚群,何怡刚.周期信号相位差的高精度数字测量[J].电工技术学报,2006,21(11):116-120 Jiang Yaqun,He Yigang.High-accuracy phase difference estimation between same frequency components in two periodic signals[J].Transactions of China electrotechnical Society,2006,21(11):116-120(in Chinese)
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