Control of a hybrid filter topology for the reduction of high frequency harmonics

Abstract

The Digital Chain is realized as an adaptive finite impulse response filter (FIR). FIR filters with the order of N consist of (N-1) time delay elements, adder and filter coefficients w(n). Based on the measured harmonics in the voltage of ZLoad the filter coefficients are adjusted using the Filtered x Least Mean Square (FxLMS) algorithm [2]. The FxLMS is a stochastic gradient descent method producing the least mean squares of the detected harmonics by updating the filter coefficients with the given formula: w(n +1) = w(n) + μe(n)x(n).