摘要
在电力系统中,间谐波检测是抑制间谐波的重要环节,准确有效地确定信号中的间谐波分量,对于改善电能质量有重要意义.FFT能够实现整数次谐波检测,对于非整数次谐波的检测存在着频率泄漏和栅栏效应,而MUSIC法需要在整个频域内进行谱峰搜索,影响其实用性.本文将FFT和MUSIC算法相结合,利用FFT缩小搜索域,再利用MUSIC进行频率细化,即克服了FFT的频率泄漏和栅栏现象,同时缩短谱峰搜索时间,可以更有效地估计出间谐波的频率,仿真试验说明了此方法的有效性及频率估计的精确度.
Along with the development of electric power system, harmonic and inter-harmonic detection plays an important role in power quality research due to the harmful impact of harmonics on power system and electric apparatus. When we use FFT to analyze harmonics and inter-harmonics, the inter-harmonics component will result in a phenomenon of frequency spectrum leakage and make the amplitude-frequency image distorted. MUSIC requires searching in the whole frequency range, which limits its real-time applications. In this paper, a proposal is given that uses FFT algorithm to pre-estimate the component frequencies of a signal, then uses MUSIC algorithm to complete the frequency search. Simulation results show the proposed method have the capability of detecting inter-harmonics with a high precision.
出处
《吉林化工学院学报》
CAS
2008年第4期44-47,共4页
Journal of Jilin Institute of Chemical Technology
基金
吉林省杰出青年科研计划资助项目(20070129)
