改进的变步长自适应谐波检测算法

基于自适应对消原理的自适应谐波检测算法因其优良的性能被广泛应用于有源滤波器,但该算法存在无法平衡稳态精度和收敛速度方面的不足。针对此不足,文中基于箕舌线函数和三阶权值系数提出了一种改进的变步长(Least Mean Square,LMS)谐波检测算法。该算法利用误差信号的自相关平均估计获得期望误差估计均值,并通过改进的箕舌线迭代函数作为核心函数来调节步长更新,之后通过推导出来的三阶权值公式代替传统的权值迭代。仿真实验结果表明,该算法在谐波检测中不但具有较快的收敛速度,也能获得较高的稳态精度。

Improved adaptive harmonic detection algorithm with variable step size

The adaptive harmonic detection algorithm based on the adaptive cancellation principle is widely used in active filters because of its excellent performance, but the algorithm has the inability to balance the steady-state accuracy and convergence speed. Aiming at this deficiency, an improved variable mean square (LMS) harmonic detection algorithm is proposed based on the versiera function and the third-order weight coefficient. The algorithm uses the autocorrelation average estimate of the error signal to obtain the mean of the expected error estimate, and adjusts the step size update by using the improved versiera function as a core function.. The traditional third-order weight formula is then used instead of the traditional weight iteration. The simulation results show that the algorithm not only has faster convergence speed in harmonic detection, but also can obtain higher steady-state accuracy.