一种模糊变步长自适应谐波检测算法

An Adaptive Harmonic Detection Method Using Fuzzy LMS Algorithm

电力有源滤波器的成功应用依赖于精确的谐波电流检测技术。基于自适应干扰对消理论,提出一种基于模糊变步长推理的最小均方差(LMS)自适应谐波检测算法。通过分析影响LMS自适应谐波算法性能的不利因素,选取均方误差变化量和输入输出信号相关函数作为参量,建立模糊推理系统,自适应地调节算法的步长,实现谐波检测过程中,既能保证较快的动态响应速度和对噪声干扰的抑制,又能保持较高的检测精度,并通过计算机仿真及物理实验验证了该算法的有效性和可行性。

The successful control of the active power filter requires interference canceling theory, an adaptive least mean squares （LMS） algorithm employing the fuzzy step size is presented for the fast detection of harmonic current in power networks. By analyzing the unfavorable factors of the LMS adaptive algorithm for harmonic detection and to establish the fuzzy inference system, the mean square error of variance and input-output signals correlation function are selected as parameters for suitable automatic adjustment of the step size. The method proposed can not only provide fast convergence and noise restraint for the tracking of fundamental and harmonic components from distorted signals, but also maintain a fairly high detection accuracy. The results of computer simulations and physical experiments verify the reliability and feasibility of the method proposed.