基于最小二乘法和独立分量分析的间谐波检测算法

Algorithm for inter-harmonic detection based on least square method and ICA

针对电力系统间谐波难于检测的问题,给出了一种基于最小二乘法和独立分量分析的间谐波检测算法。该算法利用快速傅里叶变换和最小二乘法确定基波和谐波的相关参数,构造出适当的虚拟观测信号,借助独立分量分析算法分离出基波、谐波和部分易于检测的间谐波信号,然后根据已经获得的参数再调整观测信号矩阵,从而逐次分离检测出剩余的小幅度间谐波信号。仿真结果表明,该算法在实时性要求不高的情况下,无需先验知识、无需消掉原电力系统信号中基波和谐波便可以准确检测出临近基波或谐波的小幅度间谐波。与独立分量分析算法进行比较分析,该算法检测间谐波的性能具有明显的优越性。

In this paper, a new algorithm based on least square method and FastICA algorithm is proposed to overcome the difficulty in inter-harmonic detection in power system. The algorithm combines FFT and least-squares method to determine the fundamental and harmonic parameters. And it constructs the appropriate virtual observed signals and separates the fundamental, harmonics and some easy detected inter-harmonics with the help of ICA algorithm. Then according to the estimated parameters it can adjust the observed signal matrix and detect remaining small amplitude inter-harmonic signals. The simulation results show that the algorithm can accurately detect the small amplitude inter-harmonics near fundamental and harmonic without prior knowledge and eliminating fundamental and harmonic components in the case of less real-time demand. And this algorithm has high obvious superiority with ICA algorithm.