APF中一种改进的变步长LMS自适应谐波检测算法

在有源电力滤波器(Active Power Filter, APF)的低信噪比(Signal Noise Ratio, SNR)环境下，为了提高变步长最小均方(Least Mean Square, LMS)自适应算法对谐波电流检测的跟踪速度及精度，提出改进的变步长LMS算法。该算法在MVSS-LMS算法的基础上，增加历史误差的遗忘加权和估计并控制步长更新，动态控制步长更新范围，采用滑动窗遗忘加权减小了计算复杂度。同时，对改进算法性能进行稳定性分析。实验结果表明，该算法不仅具有较快的动态响应速度，而且在APF的低信噪比情况下，稳态误差有所减小，具有较高的抗干扰能力，谐波电流检测效果较好。

An improved variable step-size LMS adaptive harmonic detection algorithm for active power filters

A new improved variable step-size LMS algorithm is proposed in order to enhance the tracking velocity and accuracy of harmonic detection by variable step-size LMS adaptive algorithm in the low signal-noise rate (SNR) conditions of APF. Based on the MVSS-LMS algorithm, the improved algorithm adds the estimation of forgetting- weighted sum of historical errors to control the step-size updating and dynamically regulate the range of step-size. Also, sliding forgetting-weighted window is introduced to reduce computational complexity. The convergence speed and steady state performance of the algorithm are analyzed. According to experimental results, this algorithm possesses faster dynamic response speed and decreases steady state errors in low SNR conditions of APF. It has the high anti-jamming capability and better effect of harmonic current detection.