Abstract:Due to spectrum leakage, traditional phase difference methods with little attenuation of side lobe led to a larger error in the measurement of power harmonic. And the selection of window is restricted because the dependence on analytic expression. This paper uses an improved phase difference method that based on Hanning window. It performs polynomial transformation on the result of fast Fourier transform(FFT) to get a new sequence, then adjusts harmonic parameters with the new sequence. To verify its performance, do simulation calculation and compare it with other common methods, simulate for 10 000 times at random frequency to calculate its standard error, shorten the sampling window to explore its real-time performance. The results show that, the new method is more accurate than other methods, when the frequency ranges between 47 Hz and 53 Hz, the accuracy of harmonic parameters reaches to 10-5. And under the 100 milliseconds sampling length, it also can satisfy the IEC 61000—4—7 standard. Taking computational accuracy into account, the correction formula is derived from Hanning window and it′s quite simple. It′s a useful harmonic parameters detection algorithm.
[1] Jun W,Huang A,Woongje S,et al.Smart grid technologies[J].IEEE Industrial Electronics Magazine,2009,3(2):16-23. [2] Chang G W,Chen I C,Teng Y F.Radial basis function based neural network for harmonic detection[J].IEEE Transactions on Industrial Electronics,2010,57(6):2171-2179. [3] 陈淑华,付青,马桂龙,等.基于神经网络自适应预测算法的谐波检测[J].电工技术学报,2011,26(1):200-207. Chen Shuhua,Fu Qing,Ma Guilong,et al.Harmonic detection based on artificial neural network and adaptive predictive algorithm[J].Transactions of China Electrotechnical Society,2011,26(1):200-207. [4] 王刘旺,黄建才,孙建新,等.基于加汉宁窗的FFT高精度谐波检测改进算法[J].电力系统保护与控制,2012,40(24):28-33. Wang Liuwang,Huang Jiancai,Sun Jianxin,et al.An improved precise algorithm for harmonic analysis based on Hanning-windowed FFT[J].Power System Protection and Control,2012,40(24):28-33. [5] 潘文,钱俞寿,周鹗.基于加窗插值FFT的电力谐波测量理论(I)——窗函数的研究[J].电工技术学报,1994,9(1):50-54. Pan Wen,Qian Yushou,Zhou E.Power harmonics measurement based on windows and interpolated FFT(I)study of windows[J].Transactions of China Electrotech-nical Society,1994,9(1):50-54. [6] Ming Z,Kaicheng L,Yisheng H.A high efficient compression method for power quality applications[J].IEEE Transactions on Instrumentation and Measurement,2011,60(6):1976-1985. [7] 赵勇,沈红,李建华,等.谐波源的识别及其与非谐波源的分离方法[J].中国电机工程学报,2002,22(5):84-87. Zhao Yong,Shen Hong,Li Jianhua,et a1.Approach of identification and separetion of harmonic source[J].Proceedings of the CSEE,2002,22(5):84-87. [8] Ferrero A,Salicone S,Toscani S.A fast,simplified frequency-domain interpolation method for the evaluation of the frequency and amplitude of spectral components[J].IEEE Transactions on Instrumentation and Measu-rement,2011,60(5):1579-1587. [9] 房国志,杨超,赵洪.基于FFT和小波包变换的电力系统谐波检测方法[J].电力系统保护与控制,2012,40(5):75-79. Fang Guozhi,Yang Chao,Zhao Hong.Detection of harmonic in power system based on FFT and wavelet packet[J].Power System Protection and Control,2012,40(5):75-79. [10]Milenko B D,eljko R D.Frequency measurement of distorted signals using Fourier and zero crossing techniques[J].Electric Power System Research,2008,78(8):1407-1415. [11]Spark Y X,Simon X Y.Power system frequency estimation using supervised Gauss-Newton algorithm[J].Measurement,2009,42(1):28-37. [12]禹永植, 张忠民, 席志红. 基于傅里叶变换的高精度频率及相量算法[J]. 电网技术, 2007, 31(23): 83-86. Yu Yongzhi, Zhang Zhongmin, Xi Zhihong. A high precision algorithm for frequency and phase based on Fourier transform[J]. Power System Technology, 2007, 31(23): 83-86. [13]陈隆道,钱照明,张圣训.周期域分析中非同步取样数据的同步化[J].电子学报,2001,29(7):1-4. Chen Longdao,Qian Zhaoming,Zhang Shengxun.Synchronization algorithm for the asynchronous sampled data set in period domain signal analysis[J].Acta Electronica Sinica,2001,29(7):1-4. [14]牛胜锁,梁志瑞,张建华,等.基于三谱线插值FFT的电力谐波分析算法[J].中国电机工程报,2012,32(16):130-136. Niu Shengsuo,Liang Zhirui,Zhang Jianhua,et al.An algorithm for electrical harmonic analysis based on triple-spectrum-line interpolation FFT[J].Proceedings of the CSEE,2012,32(16):130-136. [15]温和,滕召胜,王永,等.改进加窗插值FFT 动态谐波分析算法及应用[J].电工技术学报,2012,27(12):270-277. Wen He,Teng Zhaosheng,Wang Yong,et al.Improved windowed interpolation FFT algorithm and application for power harmonic analysis[J].Transactions of China Electrotechnical Society,2012,27(12):270-277. [16]刘海升,付志红,张淮清,等.基于Blackman-Harris相位差校正信号谐波分析方法[J].数据采集与处理,2011,26(4):468-472. Liu Haisheng,Fu Zhihong,Zhang Huaiqing,et al.Harmonic analysis based on Blackman-Harris window and phase difference correction[J].Journal of Data Acquisition & Processing,2011,26(4):468-472. [17]丁康,罗江凯,谢明.离散频谱时移相位差校正法[J].应用数学与力学,2002,23(7):729-733. Ding Kang,Luo Jiangkai,Xie Ming.The discrete spectrum phase difference correction method[J].Applied Mathematics and Mechanics,2002,23(7):729-733. [18]温和,滕召胜,卿柏元.Hanning 自卷积窗及其在谐波分析中的应用[J].电工技术学报,2009,24(2):164-169. Wen He,Teng Zhaosheng,Qing Baiyuan.Hanning self-convolution windows and its application to harmonic analysis[J].Transactions of China Electrotechnical Society,2009,24(2):164-169.