A novel adaptive harmonic detecting algorithm applied to active power filters

The performance of active power filter (APF) depends on the method applied to the harmonic current detection, a novel variable step-size LMS algorithm is proposed, where using autocorrelation time mean estimate of error signal to update the step-size, it can suppresses the effect of the harmonic components on the updating of step-size. The performance of the algorithm is validated through a simulation with MATLAB software. The result shows that the novel algorithm has advantages of a quite high detection precision, a big convergence rate and a good noise immunity performance, which is the same as theoretical analysis.