Application of Adaptive Filtering in Harmonic Analysis and Detection

As a kernel technique of active power filter (APF), harmonic detection and its tracking method are investigated in this paper. Firstly, according to APF discussed here, an adaptive notch filter is presented and the LMS algorithm is examined to meet the crucial requirements of the filter´s tracking behavior under time-varying condition. Secondly, an upgraded method is emphasized on the basis of the traditional LMS algorithm, the variable step-size method is analyzed with both its merits and demerits, in order to guarantee the convergence rate and steady-state performance, a correct-mu_max mending method is introduced as the major solution to improve the performance of variable step-size, so as to obtain good tracking reliability as well as rapidity. For better understanding, the simulation results are given out and illustrated, with the friendly toolbox of Matlab