运行扩展Prony算法对电力系统的非整次谐波进行检测.DOC

扩展Prony算法电力系统非整次谐波检测研究摘要：准确有效地检测出电力系统中各次谐波及间谐波，对于提高电能质量是至关重要的。传统的快速傅立叶变换由于频谱泄漏等原因，无法准确检测出系统中的非整次谐波。为解决这一问题，文章提出应用扩展Prony算法检测系统的非整次谐波。首先利用小波去除噪声，很好的克服Prony算法对噪声敏感这一弱点；然后通过线性预测得到模型的特征矩阵，运用奇异值分解法求解特征矩阵得到模型的特征多项式；最后运用最小二乘法求出特征多项式的根，得到非整次谐波各参数。针对信号频带宽窄可能影响算法精度这一问题，文章对不同带宽信号进行扩展Prony分析，验证算法精度。实验分析说明该算法的可行性和有效性。 关键词：扩展Prony算法；小波去噪；非整次谐波检测；FFT；信号带宽 中图分类号：TM71 文献标识码： 文章编号：1001-1390（201）00-0000-00 Wang Yu1, Zhao Qingsheng1, Guo Hehong2, Wang Zhenqi2, Zhang Xuejun3 (1. College of Electrical and Power Engineering, Taiyuan University of Technology, Taiyuan 030024, China. 2. Jinzhong Electric Power Company of SGCC, Jinzhong 030600, Shanxi, China. 3. Shanxi University, Taiyuan 030006, China) Abstract: It is especially important for improving power quality to identify all kinds of harmonics and inter-harmonics accurately and effectively in power system. Due to the spectrum leakage, the traditional Fast Fourier Transformation algorithm (FFT) cannot accurately detect the non-integral harmonics. To address this issue, the extended Prony algorithm is applied in this paper to identify the non-integral harmonics. Wavelet-de-noising method is firstly used to overcome the weakness that the Prony algorithm is noise-sensitive, and then, the eigen matrix of model is obtained by linear prediction and singular value decomposition is used to solve the eigen matrix to get characteristic polynomial of model. Finally, the least square method is used to find the root of the characteristic polynomial to get parameters of the non-integral harmonics. In view of the problem that the signal band width may affect the accuracy of the algorithm, the extended Prony algorithm is used to analyze different bandwidth signals to prove the accuracy of algorithm. Experimental analysis verifies the viability and effectiveness of the algorithm. Keywords: extended Prony algorithm, wavelet-de-noising, non-integral harmonics detection, FFT, signal bandwidth 近年来随着大量非线性电力元件被广泛使用，电力系统中谐波的含量显著增加。谐波除了含与基波成整数倍的谐波外，还存在许多与基