Yang Chao1, Zhang Huaiqing1, Wang Yao2, Li Bo3, Fu Zhihong1
1. State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University Chongqing 400044 China; 2. Chongqing Triloop Prospecting Technology Co. Ltd Chongqing 402660 China; 3. Electric Power Research Institute of Yunnan Power Grid Co. Ltd Kunming 650217 China
Abstract:A multipoint interpolated DFT correction method based on total spectral leakage suppression is proposed for the short cycles in record (CiR) of multi-frequency signal. Firstly, the spectral leakage from other frequency components is equivalently approximated to a Taylor series polynomial by the linear proportional recursive property of the maximum sidelobe decay Windows (MSDW) spectrum. The spectral parametric model of total spectral leakage is then established combined with the negative leakage component of the measured frequency. Furthermore, the corresponding equations of multipoint spectral lines are established according to the approximate order of the spectral leakage, and then the general analytical formula of multipoint frequency interpolation correction under the MSDW is derived. Finally, the least squares (LS) method is used to obtain an accurate estimation of the amplitude and phase. Multiple simulation and experimental test show that the algorithm still has high correction accuracy when the measured frequency is as low as 1.5 frequency resolutions under noise and other frequency leakage interference of equal magnitude.
[1] 王保帅, 肖霞. 一种用于谐波分析的高精度多谱线插值算法[J]. 电工技术学报, 2017, 32(15): 22-31. Wang Baoshuai, Xiao Xia.A high accuracy multi spectrum-line interpolation algorithm for harmonic analysis[J]. Transactions of China Electrotechnical Society, 2017, 32(15): 22-31. [2] Swanson D C.Precision spectral peak frequency measurement using a window leakage ratio function[J]. Mechanical Systems and Signal Processing, 2015, 54: 1-15. [3] Romano P, Paolone M.Enhanced interpolated-DFT for synchrophasor estimation in FPGAs: theory, implementation, and validation of a PMU proto- type[J]. IEEE Transactions on Instrumentation and Measurement, 2014, 63(12): 2824-2836. [4] 吴超凡, 陈隆道. 应用于电力谐波分析的改进相位差校正法[J]. 电工技术学报, 2017, 32(7): 158-164. Wu Chaofan, Chen Longdao.Improved phase differ- ence correction method applied to power harmonic analysis[J]. Transactions of China Electrotechnical Society, 2017, 32(7): 158-164. [5] Diao R, Meng Q.Frequency estimation by iterative interpolation based on leakage compensation[J]. Measurement, 2015, 59(1): 44-50. [6] Belega D, Petri D.Frequency estimation by two- or three-point interpolated fourier algorithms based on cosine windows[J]. Signal Processing, 2015, 117: 115-125. [7] Belega D, Petri D, Dallet D.Impact of harmonics on the interpolated DFT frequency estimator[J]. Mecha- nical Systems and Signal Processing, 2016, 66: 349-360. [8] Liguori C, Paolillo A, Pignotti A.Estimation of signal parameters in the frequency domain in the presence of harmonic interference: a comparative analysis[J]. IEEE Transactions on Instrumentation and Measurement, 2006, 55(2): 562-569. [9] 牛鹏辉, 涂亚庆, 张海涛. 一种实正弦信号的短时频率估计新方法[J]. 电子测量与仪器学报, 2007, 21(6): 40-44. Niu Penghui, Tu Yaqing, Zhang Haitao.New method of short-time frequency estimation for real signal[J]. Journal of Electronic Measurement and Instrument, 2007, 21(6): 40-44. [10] Belega D, Dallet D.Multifrequency signal analysis by Interpolated DFT method with maximum sidelobe decay windows[J]. Measurement, 2009, 42(3): 420-426. [11] Luo Jiufei, Xie Zhijiang, Xie Ming. Interpolated DFT algorithms with zero padding for classic windows[J]. Mechanical Systems and Signal Processing, 2016, 70-71: 1011-1025. [12] 毛育文, 涂亚庆, 张海涛, 等. 计及负频率影响的频谱分析方法及研究进展[J]. 电测与仪表, 2011, 48(5): 27-32. Mao Yuwen, Tu Yaqing, Zhang Haitao, et al.Advances and trends in spectrum analysis metho- dology with negative frequency contribution[J]. Electrical Measurement & Instrumentation, 2011, 48(5): 27-32. [13] 曾金芳, 滕召胜, 唐求. 自卷积检测方法及其在离散频谱校正中的应用[J]. 中国电机工程学报, 2014, 34(28): 4976-4982. Zeng Jinfang, Teng Zhaosheng, Tang Qiu.Self- convolution detection method and its application in discrete spectrum correction[J]. Proceedings of the CSEE, 2014, 34(28): 4976-4982. [14] 张俊敏, 刘开培, 汪立, 等. 基于主瓣宽度多谱线插值的高精度快速谐波分析算法[J]. 电工技术学报, 2018, 33(增刊1): 121-128. Zhang Junmin, Liu Kaipei, Wang Li, et al.A precise and rapid algorithm for harmonic analysis based on multi-spectrum-line in main lobe width interpolation FFT[J]. Transactions of China Electrotechnical Society, 2018, 33(S1): 121-128. [15] Candan C.A method for fine resolution frequency estimation from three DFT samples[J]. IEEE Signal Processing Letters, 2011, 18(6): 351-354. [16] 陈奎孚, 王建立, 张森文. 短记录加汉宁窗的频谱校正[J]. 振动与冲击, 2008, 27(4): 49-51. Chen Kuifu, Wang Jianli, Zhang Senwen.Spectrum correction for short records weighted by a hanning window[J]. Journal of Vibration and Shock, 2008, 27(4): 49-51. [17] Belega D, Petri D, Dallet D.Frequency estimation of a sinusoidal signal via a three-point interpolated DFT method with high image component interference rejection capability[J]. Digital Signal Processing, 2014, 24: 162-169. [18] 陈奎孚, 张森文, 郭幸福. 消除负频率影响的频谱校正[J]. 机械强度, 2004, 26(1): 25-28. Chen Kuifu, Zhang Senwen, Guo Xingfu.Spectrum rectifying with negative frequency contribution eliminating[J]. Journal of Mechanical Strength, 2004, 26(1): 25-28. [19] Aboutanios E, Mulgrew B.Iterative frequency estimation by interpolation on Fourier coefficients[J]. IEEE Transactions on Signal Processing, 2005, 53(4): 1237-1242. [20] Chen Kuifu, Cao Xu, Li Yangfeng.Sine wave fitting to short records initialized with the frequency retrieved from Hanning windowed FFT spectrum[J]. Measurement, 2009, 42(1): 127-135. [21] Borkowski J, Kania D, Mroczka J.Interpolated-DFT- based fast and accurate frequency estimation for the control of power[J]. IEEE Transactions on Industrial Electronics, 2014, 61(12): 7026-7034. [22] Belega D, Petri D.Effect of noise and harmonics on sine-wave frequency estimation by interpolated DFT algorithms based on few observed cycles[J]. Signal Processing, 2017, 140: 207-218. [23] 王泽, 杨洪耕, 王佳兴, 等. 消除负频率影响的低频间谐波快速检测方法[J]. 电力自动化设备, 2015, 35(3): 140-145. Wang Ze, Yang Honggeng, Wang Jiaxing, et al.Rapid low-frequency interharmonic detection with negative-frequency elimination[J]. Electric Power Automation Equipment, 2015, 35(3): 140-145. [24] Chen Kuifu, Jiang Jingtao, Crowsen S.Against the long-range spectral leakage of the cosine window family[J]. Computer Physics Communications, 2009, 180(6): 904-911.