电网间谐波分析的包络分解法-电力系统保护与控制.PDFVIP

第 39 卷 第 6 期 电力系统保护与控制 Vol.39 No.6 2011 年3 月 16 日 Power System Protection and Control Mar.16, 2011 电网间谐波分析的包络分解法 1 1,2 王柏林 ，熊杰锋 （1.河海大学电气工程学院，江苏 南京 210098；2.南京信息工程大学电子信息工程学院，江苏 南京 210044） 摘要：从间谐波产生的机理出发，提出一种分析电网间谐波的新方法—— 包络分解法。该方法的主要依据是：含间谐波的工 频信号一定是非平稳工频信号，间谐波信息一定包含在工频信号的包络之中。该方法的关键步骤是：从工频信号中提取包络， 对包络进行分解，按特定公式求出各次间谐波的频率、幅值。包络分解法排除了整次谐波频谱泄漏产生的虚假间谐波，基于 Matlab的仿真表明，用于实际电网时它提供的间谐波信息更为真实、精确。 关键词：谐波分析；间谐波；非平稳信号；包络；频谱泄漏 Envelope decomposition-based method for interharmonics analysis in power system 1 1,2 WANG Bo-lin ，XIONG Jie-feng （1. College of Electric Engineering，Hohai University ，Nanjing 210098 ，China ； 2. College of Electronic and Information Engineering，Nanjing University of Information Science and Technology ， Nanjing 210044 ，China ） Abstract ：Based on the mechanism of interhamonics producing ，a new algorithm, named envelope decomposition-based method ，for interharmonic analysis of power system is presented．The proposed method is mainly based on the two points that power frequency signal containing interharmonics must be non-stationary；interharmonics parameters must be restored from the envelope of the power frequency signal ．The key steps are that extracting the envelope from power frequency signal, then decomposing the envelope and finally calculating frequency and amplitude of each-order’s interharmonic based on specific formula. The fake interharmonics caused by the spectral leakage of integral harmonics are avoided. MATLAB simulation verifies that the method is more accurate f