小波变换与FFT在电网谐波检测中的应用

电力系统中大量谐波的注入使得网络电能质量明显下降,而传统的检测方法由于自身技术的限制,已经不能满足目前谐波检测对实时性和精确性的要求。该文在分析了电网谐波变化特征的基础上,结合谐波检测新理论的发展及应用实践,提出将小波变换与传统检测方法相结合的检测方案,并用仿真试验验证了该联合算法的有效性。数据结果表明:小波变换在分析复杂信号中各谐波成分时表现出了其时频局部化特性的优势,而传统的FFT可准确提取信号各成分的频谱信息,该联合检测方法有效地提高了谐波检测的精度。

Application of wavelet transform and FFT in harmonic detection of power

To inject a large amount of harmonic in power system makes the network electric energy quality decreased obviously , while the traditional detection method because of its own technical limitations, has been unable to meet the requirements of real -time and accuracy of the harmonic detection . Based on the analysis of the characteristics of power grid harmonic changes , combined with the development and application of new harmonic detection theory , detection is presented .By combining the wavelet transform and the traditional detection method , and its effectiveness is verified by simulation test of combined algorithm .Results show that：the wavelet transform in the analysis of the harmonic components in complex signal showed its time -frequency localization characteristic advantage .The traditional FFT can accurately extract signal of the spectrum information .The joint detection method effectively improves the accuracy of harmonic detection .