基于变步长LMS的APF谐波电流检测方法

Harmonic Current Detection Method Based on Variable Step Size LMS Algorithm Used in APF

有源电力滤波器(active power filer,APF)谐波电流检测环节中,针对传统定步长最小均方误差(least mean square,LMS)检测算法在稳态精度和响应速度上的缺陷,提出了一种自适应变步长LMS谐波检测算法。该算法利用历史误差数据,计算误差的功率加权并以之作为步长调节的主控因子,对步长进行调节。扰动因子的引入能够对噪声进行抑制。最后将该算法用于APF的谐波检测。仿真及实验表明,该算法不仅具有快速的动态响应特性,同时又具有较高的检测精度,能够满足APF谐波电流检测的需求。

In the process of harmonic current detection of active power filter,considering the drawback of staticaccuracy and dynamic response ability in the traditional fixed step size LMS detection method,proposed a adaptivevariable step LMS harmonic current detection algorithm. Using the history error data,the algorithm calculated thepower weight of error and used it as the main factor to regulate the step size. The noise could be suppressed byintroducing the disturbance factor. And the algorithm was used to detect the harmonic current in APF. The results ofsimulation and experiment show that,the method is more advanced both in dynamic response and detection accuracy,and satisfy the requirement of harmonic detection for APF.